Hubbry Logo
Crimp (joining)Crimp (joining)Main
Open search
Crimp (joining)
Community hub
Crimp (joining)
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Crimp (joining)
Crimp (joining)
Crimp (joining)
View on Wikipedia
from Wikipedia
Crimp Tool For Bootlace Ferrules
Crimp tool for 0.14 mm2 to 10 mm2 (26–8 AWG) insulated and non-insulated ferrules

Crimping is a method of joining two or more pieces of metal or other ductile material by deforming one or both of them to hold the other. The bend or deformity is called the crimp.[1][2] Crimping tools are used to create crimps.

Crimping is used extensively in metalworking, including to contain bullets in cartridge cases, for electrical connections, and for securing lids on metal food cans. Because it can be a cold-working technique, crimping can also be used to form a strong bond between the workpiece and a non-metallic component. It is also used to connect two pieces of food dough.

Tools

[edit]

A crimping tool or crimp tool is used to create crimps. Crimping tools range in size from small handheld devices, to benchtop machines used for industrial purposes, to large fully-automatic wire processing machines for high-volume production.[1][2]

For electrical crimps, a wide variety of crimping tools exist, and they are generally designed for a specific type and size of terminal. Handheld tools (sometimes called crimping pliers) are common. These often use a ratcheting mechanism to ensure sufficient crimping force has been applied. Apart from handheld tools, crimping tools can also include sophisticated electrically powered hydraulic types and battery operated tools that cover the entire size range and type of conductors, designed for mass production operations.[3]

Electrical crimp

[edit]
F connectors crimped on to coaxial cable. The bottom middle cable is missing its crimping collar.
A wire and connector in a crimping tool

An electrical crimp is a type of solderless electrical connection which uses physical pressure to join the contacts. Crimp connectors are typically used to terminate stranded wire.[4] Stripped wire is inserted through the correctly sized opening of the connector, and a crimper is used to tightly squeeze the opening against the wire. Depending on the type of connector used, it may be attached to a metal plate by a separate screw or bolt or it could be simply screwed on using the connector itself to make the attachment like an F connector.

Characteristics

[edit]
Close-up of two ring-tongue terminals before (left) and after (right) crimping[5]

The benefits of crimping over soldering and wire wrapping include:

  • A well-engineered and well-executed crimp is designed to be gas-tight, which prevents oxygen and moisture from reaching the metals (which are often different metals) and causing corrosion
  • Because no alloy is used (as in solder) the joint is mechanically stronger[6][7]
  • Crimped connections can be used for cables of both small and large cross-sections, whereas only small cross-section wires can be used with wire wrapping[6][3]

Crimping is normally performed by first inserting the terminal into the crimp tool. The terminal must be placed into the appropriately sized crimp barrel. The wire is then inserted into the terminal with the end of the wire flush with the exit of the terminal to maximize cross-sectional contact. Finally, the handles of the crimp tool are used to compress and reshape the terminal until it is cold-welded onto the wire.[3]

The resulting connection may appear loose at the edges of the terminal, but this is desirable so as to not have sharp edges that could cut the outer strands of the wire. If executed properly, the middle of the crimp will be swaged or cold-formed.

More specialized crimp connectors are also used, for example as signal connectors on coaxial cables in applications at high radio frequencies (VHF, UHF) (see below[broken anchor]). These often require specialised crimping tools to form the proper crimp.[8]

Crimped contacts are permanent (i.e. the connectors and wire ends cannot be reused).[9]

Theory

[edit]

Crimp-on connectors are attached by inserting the stripped end of a stranded wire into a portion of the connector, which is then mechanically deformed by compressing (crimping) it tightly around the wire.[10] The crimping is usually accomplished with special crimping tool such as crimping pliers. A key idea behind crimped connectors is that the finished connection should be gas-tight.

Effective crimp connections deform the metal of the connector past its yield point so that the compressed wire causes tension in the surrounding connector, and these forces counter each other to create a high degree of static friction which holds the cable in place. Due to the elastic nature of the metal in crimped connections, they are highly resistant to vibration and thermal shock.[11]

Two main classes of wire crimps exist:[12]

  • Closed barrel crimps have a cylindrical opening for a wire, and the crimping tool deforms the originally circular cross section of the terminal into some other shape. This method of crimping is less resilient to vibration.
  • Open barrel crimps have "ears" of metal that are shaped like a V or U, and the crimp terminal bends and folds them over the wire prior to swaging the wire to the terminal. Open-barrel terminals are claimed to be easier to automate because of avoiding the need to funnel stranded wire into the narrow opening of a barrel terminal.

In addition to their shape, crimped connectors can also be characterized by their insulation (insulated or non-insulated), and whether they crimp onto the conductor(s) of a wire (wire crimp) or its insulation (insulation crimp).[13]

Shapes

[edit]

Applications

[edit]
Blade connectors (bottom), ring and spade connectors (top), and bullet connectors (right)

Crimped connections are common alternatives to soldered connections. There are complex considerations for determining which method is appropriate – crimp connections are sometimes preferred for these reasons:

  • Easier, cheaper, or faster to reproduce reliably in large-scale production
  • Fewer dangerous or harmful processes involved in termination (soldered connections require aggressive cleaning, high heat, and possibly toxic solders)
  • Potentially superior mechanical characteristics due to strain relief and lack of solder wicking

Crimped connectors fulfill numerous uses, including termination of wires to screw terminals, blade terminals, ring/spade terminals, wire splices, or various combinations of these. A tube-shaped connector with two crimps for splicing wires in-line is called a butt splice connector.

Single-wire crimp terminals include:

  • Blade or quick disconnect (e.g., Faston or Lucar)
  • Bullet (e.g. Shur-Plug)
  • Butt splice
  • Flag tongue
  • Rectangular tongue
  • Hook tongue
  • Spade tongue (flanged, short spring, long spring)
  • Ring tongue (slotted, offset)
  • Multiple stud
  • Packard 56
  • Pin (SAE/J928)[19]
  • Wire pin

Crimping is also a common technique to join wires to a multipin connector, such as in Molex connectors or modular connectors.

Circular connectors using crimp contacts can be classified as rear release or front release, referring to the side of the connector where the pins are anchored:[20]

  • Front release contacts are released from the front (contact side) of the connector, and removed from the rear. The removal tool engages with the front portion of the contact and pushes it through to the back of the connector.
  • Rear release contacts are released and removed from the rear (wire side) of the connector. The removal tool releases the contacts from the rear and pulls the contact out of the retainer.

Crimp connections are used typically to attach RF connectors, such as BNC connectors, to coaxial cables[21] quickly, as an alternative to soldered connections. Typically the male connector is crimp-fitted to a cable, and the female attached, often using soldered connections, to a panel on equipment. A special power or manual tool[22] is used to fit the connector. Wire strippers which strip outer jacket, shield braid, and inner insulation to the correct lengths in one operation[23] are used to prepare the cable for crimping.

Quality

[edit]

A crimped connection will only be reliable if a number of criteria are met:

  • All strands have been deformed enough to cold-flow into the terminal body[24]
  • The compression force is not too light, nor too strong[25]
  • The connector body is not overly deformed
  • Wires must be in solid working condition, cannot have scrapes, nicks, severing or other damages
  • Insulation should not show any signs of pinching, pulling, fraying, discoloration, or charring [26]
  • Large voids are not left inside the crimp (caused by not enough wire inside the connector)
  • The wire should have as many strands as possible, so that a few damaged or uninserted wires will not adversely affect the crimp density, and thus degrade the electrical and mechanical properties of the connection.[6]

Micrographs of the crimped connections can be prepared to illustrate good and bad crimps for training and quality assurance purposes. The assembled connection is cut in cross-section, polished and washed in nitric acid to dissolve any copper dust that may be filling voids leading to a false indication of a good crimp.

Terminal insulation colors

[edit]
Standard FASTON terminal colors[27]
Insulation color Wire gauge (AWG) Comments
Yellow 26–22
Transparent 24–20
Red 22–18
Blue 16–14
Yellow/Black 16–14 Heavy duty
Yellow 12–10
Red 8
Blue 6
Yellow 4
Red 2
Blue 1/0
Yellow 2/0
Red 3/0
Blue 4/0

Other uses

[edit]
Crimped connectors on hydraulic hose

Crimping is most extensively used in metalworking. Crimping is commonly used to fix bullets in their cartridge cases, for rapid but lasting electrical connections, for securing lids on metal food cans, and for many other applications.

Bullets

[edit]
Main article: Case mouth

Canning

[edit]
Main article: Steel and tin cans § Fabrication of cans

Jewelry

[edit]

In jewelry manufacture, crimp beads, or crimp tubes, are used to make secure joints in fine wire, such as used in clasps or tie loops. A crimped lead (or other soft metal) seal is attached to secure wires used to secure fasteners in aircraft, or to provide visual evidence of tampering when securing a utility meter or as a seal on cargo containers.

Plumbing

[edit]

In plumbing, there is a trend in some jurisdictions towards the use of crimped fittings to join metallic pipes, replacing the traditional soldering or "sweating" of joints. This trend is driven in part by increased restrictions or bans of processes involving open flames, which may now require costly special permits.

Sheet metal

[edit]

When joining segments of tubular sheet metal pipe, such as for smoke pipes for wood stoves, downspouts for rain gutters, or for installation of ventilation ducting, one end of a tube is treated with a crimping tool to make a slip joint into the next section of duct. The joint will not be liquid-tight but will be adequate for conveying low pressure fluids. Crimp joints may be arranged to prevent accumulation of dirt.

Food

[edit]

Crimping is often used around the edges of pies and filled pasta like ravioli to seal the insides by connecting the top and bottom dough layers. This can be done with fingers, a fork, or a crimping tool. A jagging iron, also known as a crimping wheel, or jagger, consists of a handle and a wheel with a wavy pattern. There are also crimping tongs.

History

[edit]

The technique of soldering wires has remained common for at least a century, however crimp terminals came into use in the middle of the 20th century. In 1953, AMP Incorporated (now TE Connectivity) introduced crimp barrel terminals, and in 1957 Cannon Brothers experimented with machined contacts integrating crimp barrels.[28] During the 1960s, several standards for crimp connectors were published, including MS3191-1, MS3191-4 and MIL-T-22520. In 2010, the predominant standard for crimp connectors changed to MIL-DTL-22520.[29]

See also

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Crimp (joining)

View on Grokipedia
from Grokipedia
Crimping is a solderless mechanical joining technique that creates permanent, electrically conductive, and mechanically connections by deforming one or more ductile materials, typically metals, around another component using compressive . The process involves inserting a conductor or part into a crimp barrel or and applying pressure with specialized tools, such as ratcheting , hydraulic presses, or automated machines, to form a gas-tight bond that ensures reliable electrical and structural integrity without heat or adhesives. This method is extensively applied in industries requiring robust, reproducible connections, including electrical and electronics for wire terminations in harnesses, where it replaces to avoid issues like joints or residues. In and automotive sectors, crimping adheres to stringent standards for stranded wire connections, ensuring tensile strengths of at least 60% of the wire's capacity and preventing failures in harsh environments. Additional uses span tubular assemblies in and , where hydraulic or electromagnetic variants join pipes and fittings efficiently. Key advantages of crimping include rapid production cycles, preservation of material flexibility, and elimination of health risks from fumes, while relies on force-displacement monitoring and pull testing to verify consistency. Standards such as NASA-STD-8739.4 and DIN EN 60352-2 guide implementation, emphasizing tool calibration and 100% inspection to achieve uniform results across applications.

Overview and Principles

Definition and Process

Crimping is a cold-working process in which a ductile , typically metal, is plastically deformed to form a secure with another component, without the application of heat, adhesives, or auxiliary fasteners. This deformation creates an or form-fit connection by narrowing, necking, or beading one part—often a hollow or barrel—around an inner element, such as a wire, tube, or rod. The process relies on the to achieve a permanent bond through compression, commonly used in both electrical and non-electrical applications like wiring harnesses and systems. Basic types include open-barrel crimps, where a U- or F-shaped barrel is compressed around the joined elements, and closed-barrel crimps, where a pre-formed cylindrical barrel fully encloses the connection before deformation. The crimping process generally involves four key steps to ensure a reliable . First, materials are prepared by cutting to length and, if applicable, stripping insulation or outer layers to expose the joining surfaces without damaging the core. Second, the components are aligned by inserting the inner material—such as a conductor or pipe—fully into the crimp barrel or , ensuring proper seating against the base. Third, deformation occurs through controlled compression using a crimping tool or die, which applies precise to plastically shape the outer material around the inner one, forming the interlocking grip; this step often utilizes mechanisms for consistent pressure. Finally, the joint undergoes , including visual checks for uniform deformation and mechanical pull tests to verify tensile strength and secure hold. Various hand or automated tools, such as or presses, facilitate this compression, though selection depends on the application scale. Crimping offers several advantages, including a permanent, vibration-resistant connection that preserves conductivity and integrity without introducing thermal stresses or fillers. It enables quick assembly, cost-effective production, and compatibility with dissimilar , making it suitable for high-volume . However, disadvantages include the need for exact force application to prevent over-compression, which can cause cracking or weak bonds, and under-compression, leading to loose fits; mismatched tools and components exacerbate these risks, potentially resulting in failure under load.

Mechanical Theory

Crimping relies on the deformation of ductile materials under compressive forces to form secure mechanical joints. In this process, an applied force exceeds the material's yield strength, initiating permanent deformation where the atomic structure rearranges without fracturing, allowing the components to conform tightly to one another. Ductile metals like or aluminum are ideal, as they exhibit significant elongation before failure, enabling the necessary flow during compression. As deformation proceeds, occurs, increasing the material's resistance to further strain through interactions, which strengthens the joint by raising the local yield stress. The force required to achieve yielding in crimping derives from fundamental stress-strain relationships. The stress-strain curve of a ductile shows an initial elastic region followed by yielding, where plastic flow begins at the yield stress σy\sigma_y. The applied crimp force FF to initiate this is given by F=σy⋅AF = \sigma_y \cdot A, with AA as the contact area under compression. This equation stems from the definition of engineering stress σ=F/A\sigma = F / A; at the yield point on the stress-strain curve, σ=σy\sigma = \sigma_y, so rearranging yields the force formula. During crimping, the force must surpass this threshold across the deforming region to ensure sufficient plastic flow, though actual implementation accounts for geometry and multi-axial stresses. Joint integrity in crimping depends on several material and process factors. Material governs the extent of deformation possible without cracking, with higher promoting better conformity and load distribution. influences initial contact and ; rougher surfaces enhance mechanical interlocking by increasing frictional resistance to slippage, as seen in studies where increased roughness on mandrels boosted crimp strength in aluminum tubes. distribution, arising from uneven plastic straining and elastic recovery, creates compressive forces that maintain grip; improper distribution can lead to stress concentrations and reduced . Friction and mechanical interlock are essential for preventing axial slippage under load. During deformation, compressive forces cause the crimp barrel to extrude around the core material, forming an interlock where deformed features embed into one another, resisting pull-out. at the interface, governed by coefficients typically around 0.15–0.2 for metal contacts, amplifies this by opposing relative motion; in the of deformation, initial sliding gives way to sticking as normal rises, with the interlock visualized as overlapping radial compressions that create a tortuous path for separation. This combined action ensures the joint's reliability by distributing shear stresses effectively.

Tools and Techniques

Manual Crimping Tools

Manual crimping tools encompass hand-held devices designed for applying compressive force to connectors, such as electrical terminals, through manual operation, making them suitable for small-scale or field-based tasks. These tools primarily include -style crimpers, crimpers, and hydraulic hand presses, each varying in force application and precision. -style crimpers resemble standard with indented jaws for basic deformation, while crimpers incorporate a mechanical ratchet to control the crimping cycle, and hydraulic hand presses use a manual or to generate higher via displacement. Key features enhance and consistency in these tools. Adjustable or interchangeable dies allow adaptation to different wire gauges and connector sizes, ensuring proper fit without damaging materials. Ergonomic handles with soft grips reduce operator fatigue during repeated use, often featuring optimized angles for access in confined spaces. Ratchet mechanisms in dedicated crimpers provide a full-cycle lock that prevents release until sufficient is applied, promoting uniform deformation akin to basic mechanical principles of controlled compression. Hydraulic models include a system for amplifying hand , typically up to several tons, with emergency release valves for safety. Operation of manual crimping tools follows a standardized sequence to achieve reliable joints. First, select the appropriate die size based on the wire and connector specifications, often indicated by color-coding or markings on the tool. Insert the prepared wire—stripped of insulation and twisted for solidity—into the connector, then position the assembly within the die jaws or press head. Squeeze the handles firmly; in ratcheting tools, the mechanism advances incrementally until the cycle completes and auto-releases, while hydraulic presses require pumping the lever until the desired pressure gauge reading is reached. Finally, release the tool and inspect the crimp, often by a pull test to verify integrity. Despite their portability, manual crimping tools have inherent limitations that restrict their application to low-volume work, such as DIY electrical repairs or prototyping. Inconsistent force application, particularly in pliers-style models reliant on user strength, can result in under-crimping, which weakens connections, or over-crimping, which damages components. Even designs, while more consistent, may not achieve the precision of automated systems for high-reliability demands, and hydraulic hand presses can be bulkier and slower for repetitive tasks due to manual pumping. These tools are best suited for occasional use where mobility outweighs the need for production-scale efficiency.

Automated Crimping Equipment

Automated crimping equipment encompasses industrial systems designed for high-volume, high-precision joining of materials, particularly in wire harness and assembly lines, where manual methods are insufficient for . These machines integrate crimping operations with ancillary processes like , stripping, and verification to streamline production workflows. Unlike manual tools, automated systems employ powered actuators and control mechanisms to achieve consistent results across thousands of cycles, enabling integration into flexible environments. Common types include pneumatic presses, which utilize to drive the crimping action, offering rapid cycle times suitable for medium-force applications. Servo-electric crimpers, powered by electric motors and actuators, provide programmable motion profiles for enhanced control over force and position. Robotic arms equipped with crimp heads extend to multi-axis tasks, allowing for complex orientations and integration with vision systems for adaptive handling in dynamic production lines. Key components of these systems feature programmable controllers that oversee operations and monitor parameters in real time, ensuring compliance with specified tolerances. Interchangeable tooling accommodates various terminal sizes and shapes, facilitating quick changeovers between jobs without extensive . Sensors, including force transducers and position encoders, form feedback loops that detect deviations during the crimp cycle, enabling immediate adjustments or rejection of substandard parts. Automation yields significant advantages, such as superior through closed-loop control, which maintains uniform crimp profiles across high volumes and reduces variability compared to pneumatic-only systems. Processing speeds reach up to 1,800 crimps per hour in advanced models, far surpassing manual rates of 50-100 per hour, while data logging capabilities capture metrics like force curves and cycle times for and process optimization. These features support by flagging anomalies, minimizing defects and rework in industries demanding reliability, such as and automotive. Safety integrations are paramount, with full enclosures shielding operators from moving parts and pinch points, often complemented by light curtains for access detection. Emergency stop buttons, typically door-mounted or foot-pedal activated, halt operations instantly upon activation, while programmable force limits prevent overloads that could damage tooling or components. These measures align with industrial standards to mitigate risks in high-speed environments, promoting operator safety without compromising throughput.

Electrical Applications

Terminal Characteristics and Shapes

Electrical crimp terminals are engineered components designed to form secure, conductive connections between wires and interfaces, featuring specific physical properties that ensure reliability in electrical systems. These terminals typically consist of a barrel section for wire attachment and a or area for connection to devices or other conductors. Key characteristics include high electrical conductivity, mechanical durability, and compatibility with various wire sizes to minimize resistance and prevent failures under or . The primary material for crimp terminals is copper alloys, selected for their excellent electrical conductivity and formability during deformation. Common compositions include (a copper-tin-phosphorus ) for spring-like resilience in high-vibration environments, (copper-zinc ) for enhanced strength and resistance, and tin-plated for improved and protection against oxidation. These alloys typically contain 70-99% , with additives like tin (2-8%) or (up to 30%) to balance conductivity—often exceeding 20% IACS (International Annealed Copper Standard)—and mechanical properties such as tensile strength above 300 MPa. Barrel dimensions are precisely engineered to accommodate the wire's cross-sectional area, with typical inner diameters ranging from 0.5 mm for fine wires to over 10 mm for heavy-duty applications, and lengths of 5-15 mm to provide sufficient grip without excessive material use. The barrel often features an open "U" shape with wings that fold during crimping, ensuring 360-degree contact around the wire strands. Tongue designs vary by application, including ring shapes for bolt mounting (with inner diameters matching stud sizes from #6 to 1/2 inch), or types for quick insertion under screws, and configurations for space-constrained panel connections; these tongues are typically 0.8-2 mm thick and 5-20 mm wide to optimize current flow and mechanical interlocking. Common crimp shapes dictate the deformation pattern of the barrel, influencing the uniformity of compression and gas-tight seal formation. The F-crimp (also known as B-crimp) involves two parallel indents on opposite sides of the barrel, creating a rectangular profile that deforms the metal inward to grip the wire strands firmly while allowing slight wire compression for flexibility in smaller gauges; this shape is prevalent in insulated terminals up to 50 mm². The square crimp flattens the barrel into four equal sides, producing a compact, uniform deformation ideal for ferrules in terminal blocks, where the flat surfaces facilitate insertion into narrow slots and minimize strand damage through even pressure distribution. Hexagonal crimps form six-sided polygons around the wire, approximating a circular compression that distributes force radially for optimal contact in conductors, often achieved in one or two passes to create a smooth "collar" at the crimp ends without sharp edges. These shapes are selected based on wire material and tool dies, with hexagonal being the most versatile for both and aluminum to achieve deformation heights of 70-80% of the original barrel dimension. Sizing standards for crimp terminals are aligned with systems, primarily the (AWG) in , to ensure a precise fit that avoids loose connections or over-compression. Terminals are rated for specific AWG ranges, such as 22-18 AWG (0.3-1 mm²) for signal wires or 12-10 AWG (3-6 mm²) for power applications, with barrel capacities calculated via Circular Mils Area (CMA) to match the wire's stranded or solid construction—for instance, an 18 AWG wire with 19 strands (approximately 1620 CMA) requires a terminal sized to match this capacity to prevent strand breakage. Proper matching, often verified through color-coded insulation (e.g., blue for 16-14 AWG), ensures the crimp height is 85-95% of the wire diameter, promoting reliable conductivity below 1 mΩ per connection. Insulation integration in crimp terminals enhances safety and strain relief by incorporating features that secure the wire's outer sheath without compromising the conductor crimp. Many designs include a dual-barrel structure with an outer insulation grip that deforms around the wire's insulation diameter (e.g., 1.5-3 mm for standard PVC), using or PVC sleeves rated to 105°C for and resistance. These sleeves are crimped simultaneously with the conductor barrel, forming a firm but non-piercing hold to accommodate sleeving materials like for added . In specialized cases, terminals employ insulation displacement contacts (IDC) where sharp lances pierce the insulation directly, eliminating stripping for 22-14 AWG wires and creating multiple gas-tight points without separate sleeving.

Crimping Theory and Quality Factors

In electrical crimping, the primary objective is to form a gas-tight seal between the wire conductor and the terminal, which excludes , oxygen, and corrosive gases from the interface, thereby preventing oxidation and ensuring long-term reliability. This seal promotes a cold-weld-like bond through high-pressure deformation, maximizing metal-to-metal contact and minimizing electrical resistance for efficient current flow. The RR in such a crimp is governed by the R=ρLA,R = \frac{\rho L}{A}, where ρ\rho is the material's resistivity, LL is the effective contact length, and AA is the contact area; optimizing AA through proper crimping reduces RR significantly. Quality assessment of electrical crimps relies on several key factors to verify mechanical integrity and electrical performance. Pull-out strength testing measures the tensile force required to separate the wire from the terminal, with minimum values such as 50 lbs for 16-gauge wire ensuring robustness against vibration and handling. Crimp height, measured using a micrometer from the crimp's top surface to its bottom radial surface, confirms adequate compression within specified tolerances, typically correlating with optimal conductor deformation. Microscopic inspection of cross-sectioned samples detects voids or gaps in the crimp interface, which could compromise the gas-tight seal and increase resistance. Common defects in electrical crimping include bird-caging, where wire strands fan out or separate near the crimp due to excessive bending or improper insertion, and inadequate cold welds, resulting in loose interfaces prone to or high resistance. These issues are largely prevented through precise tooling , such as applicators with controlled force and wire guides to ensure uniform strand alignment during compression. The IPC/WHMA-A-620 standard establishes acceptability criteria for crimp profiles, including conductor placement, deformation limits, and insulation support, classifying assemblies into performance levels (Class 1 for general , Class 2 for dedicated service, and Class 3 for high-reliability applications) to guide quality validation.

Common Uses and Standards

Electrical crimping is widely employed in wiring harnesses for the , where it ensures reliable connections between wires and components to support vehicle electrical systems, such as power distribution and integration. In applications, crimped connections form critical parts of electrical wiring interconnection systems (EWIS), providing durable terminations for and control systems under demanding operational conditions. Consumer also rely on crimping for (PCB) terminations, enabling compact and efficient in devices like smartphones and appliances. Specific examples include battery connections in vehicles, where heavy-duty crimp terminals secure high-current links to prevent failures in power delivery. Industry standards govern crimp performance to ensure safety and reliability, with UL 486A-B specifying requirements for wire connectors, including testing for tensile strength, electrical conductivity, and suitability for or aluminum conductors in various applications. For , SAE AS7928 establishes specifications for insulated and uninsulated crimp-style terminal lugs and splices, emphasizing material integrity, crimping procedures, and qualification testing to meet high-reliability needs. Insulation color coding aids in identification, following conventions where red denotes 22-18 AWG terminals, blue for 16-14 AWG, and yellow for 12-10 AWG, facilitating quick selection and reducing installation errors. Crimped connections excel in high-vibration and harsh environments, such as automotive engines or aerospace fuselages, due to their gas-tight seal that resists loosening from mechanical stress, moisture, or temperature extremes. Standards like SAE AS7928 incorporate vibration and environmental exposure tests to validate performance in these conditions. As electronic devices trend toward , crimping standards have evolved to support finer wire gauges and smaller terminal sizes, with updates to UL 486A-B and similar norms addressing reduced pitches (e.g., below 2.54 mm) while maintaining pull-out strength and for compact applications like and wearables.

Non-Electrical Applications

Plumbing and Piping

In plumbing and piping systems, crimping serves as a mechanical joining method to create secure, leak-proof connections between pipes and fittings, particularly for flexible tubing and rigid metal pipes. For cross-linked polyethylene (PEX) tubing, the process involves sliding a crimp ring or cinch clamp over the end of the tubing, inserting a barbed metal or fitting into the tubing, and then using a specialized tool to compress the ring or clamp uniformly around the joint. This compression deforms the ring or clamp, gripping the tubing and fitting to form a watertight seal without adhesives or heat. Copper crimp rings, typically made from annealed copper, are compressed using a manual or ratcheting crimp tool that applies even pressure across the ring's circumference. Alternatively, stainless steel cinch clamps—also known as ear-type or pinch clamps—are secured with a cinch tool that pinches the clamp's protruding ears together, creating an interlocking seal. These methods are widely used for PEX due to the material's flexibility and expansion properties, ensuring connections withstand thermal cycling and pressure fluctuations. For pipes, crimping is achieved through fittings, where a specialized sealed fitting is slipped over the pipe end, and a tool with interchangeable jaws compresses a or around the joint. This process, often referred to as press-connect joining, uniformly deforms the to lock the fitting in place, creating a rigid, vibration-resistant connection suitable for high-pressure lines. Unlike manual crimping for PEX, press systems require powered tools to generate the necessary force—up to several tons—for larger diameters, making them efficient for professional installations in straight runs or complex layouts. Tools like cinch clamps for PEX can sometimes adapt to smaller applications, but dedicated press tools are standard for compliance and reliability. Materials for crimp components in plumbing prioritize corrosion resistance and compatibility with system fluids. Copper crimp rings offer malleability for even deformation on PEX, providing durability in neutral pH water environments, while stainless steel cinch clamps excel in aggressive or chlorinated water due to their superior resistance to pitting and scaling. Metal ferrules, often brass or bronze inserts within the fittings, enhance grip and prevent tubing slippage under pressure, ensuring long-term integrity in dynamic systems. Although polymer-based rings exist for low-pressure flexible lines, metal options dominate plumbing for their mechanical strength and ability to maintain seals over decades. Crimping finds extensive use in residential water distribution lines, where PEX tubing connects manifolds to fixtures, and in radiant heating systems, such as hydronic loops that circulate heated for efficient space conditioning. In lines, crimped joints enable easy routing through walls and ceilings without elbows, reducing labor and material costs. For radiant heating, oxygen-barrier PEX with crimped connections prevents in boilers by maintaining closed-loop integrity. These applications benefit from crimping's speed and safety compared to , as it eliminates open flames, minimizing fire risks in occupied structures and avoiding heat distortion in nearby materials. Standards ensure crimped plumbing joints meet performance criteria for safety and reliability. The ASTM F1807 specification governs metal insert fittings with copper crimp rings for SDR9 PEX tubing, requiring connections to withstand 100 psi at temperatures up to 180°F (82°C) for hot- and cold-water systems. Complementing this, ASTM F2098 covers stainless steel cinch clamps, mandating uniform compression for leak-free performance under similar conditions. For PEX tubing itself, ASTM F876 establishes a hydrostatic pressure rating of 160 psi at 73°F (23°C), with crimped assemblies tested to three times the working pressure. Copper press fittings adhere to ASTM B1029, verifying leak-tight joints at system pressures typically up to 200 psi for potable water. These standards collectively confirm leak-proof seals in residential applications, where operating pressures rarely exceed 80 psi.

Jewelry and Sheet Metal

In jewelry making, crimping serves as a key technique for securing beads and clasps to beading wire, ensuring durable and seamless connections without visible knots. Tube crimps, small cylindrical metal sleeves, are threaded onto the wire after passing through a bead or clasp, then compressed using specialized pliers to grip the wire firmly and create a loop for attachment. Calottes, also known as clamshell or bead tips, function similarly by enclosing the wire end and knot, with their hinged design allowing for a clean fold and crimp to hide imperfections while providing a polished endpoint. These methods rely on manual crimping tools, such as chain-nose or crimping pliers, to fold the metal precisely, resulting in an aesthetic finish that enhances the overall elegance of necklaces, bracelets, and earrings. Crimps in jewelry are typically crafted from precious metals like , 14k , or to match the design's components and resist tarnishing or over time. The primary advantage lies in achieving a professional, knot-free appearance that maintains the fluidity of beaded strands while preventing slippage, making it ideal for lightweight, decorative pieces where durability meets visual appeal. In fabrication, crimping forms strong, interlocking seams essential for constructing ducts, roofing panels, and enclosures, particularly in HVAC systems. locks involve bending one sheet's edge into a right-angle pocket and the mating sheet into a that inserts into the pocket, followed by crimping the exposed with a , roller, or seamer to lock the securely. Snap-lock seams, a simpler variant, feature a pre-formed male tab on one edge that snaps into a female channel on the other, then crimped along the length using hand tools or powered rolls to flatten and seal the connection. These processes typically employ galvanized sheets, which provide resistance through their coating, suitable for indoor and outdoor applications exposed to moisture. The advantages of crimped seams in include creating airtight and leak-proof joins critical for efficient in HVAC ducts, reducing energy loss and ensuring system integrity without the need for additional fasteners or adhesives. In roofing, these seams offer a weather-resistant, low-profile finish that enhances while minimizing visible hardware.

Food Processing and Canning

In and , crimping plays a critical role in creating secure, sanitary seals for perishable products, ensuring preservation by preventing microbial contamination and extending . One primary application is the double-seam crimping of metal can lids, where the can body's is interlocked with the lid's curl using specialized seaming machines to form a filled with a rubber-like compound that fills voids and resists abuse. This process typically involves two rolling operations on rotary machines: the first hooks the lid into place, and the second tightens the seam to interlock multiple layers of metal, creating an airtight barrier that inhibits spoilage from , oxygen, or external contaminants. Beyond , crimping is employed in various preparation techniques to seal dough-based or encased products, maintaining integrity during cooking or storage. For instance, pie crusts are crimped along their edges using manual tools like or fingers to fold and press the , preventing filling leakage and enhancing structural stability in baked goods. Similarly, edges are sealed by pressing moistened layers together with a or roller, expelling air to avoid bursts during and ensuring the filling remains contained. In meat processing, sausage casings—often or fibrous—are crimped at the ends using pliers or clips to secure the meat emulsion, facilitating portioning and preventing exposure during or cooking. These methods prioritize , as improper seals can lead to in high-moisture environments. Regulatory standards, particularly from the U.S. (FDA), mandate rigorous testing for seam integrity to safeguard in canned goods. Under 21 CFR 113.60, manufacturers must visually inspect and measure double seams for dimensions like thickness, width, and hook lengths, with at least one can per seaming head examined periodically by a qualified inspector. Vacuum testing, such as the NFPA method applying 15-25 inches of mercury, detects microleaks by observing bubble formation in submerged samples, ensuring no breaches that could allow entry. These guidelines emphasize for leaks, aligning with broader low-acid canned food requirements to prevent and other hazards. Historically, double-seam crimping emerged in the late as a sanitary advancement over soldered seals, enabling reliable for military and civilian use by creating durable hermetic closures without lead-based materials. Today, via high-speed rotary seamers processes thousands of cans per minute, integrating with filling lines for efficient, consistent seals in industrial settings.

Ammunition and Bullets

In manufacturing and reloading, crimping secures the to the cartridge case mouth through controlled mechanical deformation, ensuring the remains fixed during handling, feeding, and firing. This process primarily involves roll crimping, where the case mouth is rolled inward into a groove () on the , or taper crimping, which gradually narrows the case mouth to grip the bullet's shank without deep indentation. These methods apply compressive force to the typically cartridge case, which is composed of 70% and 30% for durability and resistance, against bullets often featuring a lead core jacketed in or for controlled expansion and reduced barrel fouling. Roll crimping is commonly used for cartridges and certain , such as those headspacing on the case rim, where the die's internal shoulder rolls the case mouth tightly against the bullet's to prevent forward movement under or impact. In contrast, taper crimping suits semi-automatic s and some s, like 9 mm Luger loads, by applying a , angled compression that supports headspacing on the case mouth while facilitating smooth chambering in tubular magazines or autoloading actions. applications often favor roll crimps for high- environments to maintain bullet position, whereas rounds prioritize taper crimps to avoid excessive deformation that could hinder feeding. Crimping plays a critical role in ballistic safety by preventing bullet setback, where the projectile shifts deeper into the case during storage or cycling, potentially elevating chamber pressure beyond safe limits and risking firearm damage or injury. Proper crimping ensures consistent ignition and pressure curves, as excessive or insufficient grip can alter the burn rate of propellant or cause erratic velocities; for instance, over-crimping may initially spike pressure by delaying bullet release, while under-crimping risks inconsistent performance. The Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) establishes baseline cartridge dimensions, including case mouth specifications, to guide crimping practices that maintain interchangeability and safety, with recommended crimp depths typically ranging from 0.010 to 0.020 inches to achieve secure retention without compromising case integrity. For handloaders, specialized reloading dies—such as seating dies with integrated crimp features or dedicated factory crimp dies—allow precise control over the process, often performed in separate steps to first seat the bullet to the desired cartridge overall length () and then apply the crimp. These tools, commonly from manufacturers like RCBS or Lee Precision, enable reloaders to adjust force for versus handgun needs, ensuring compliance with SAAMI guidelines while optimizing for specific firearms.

Historical Development

Early Origins

The rudimentary forms of crimping emerged in ancient during the , around 3000 BCE, where artisans employed riveting techniques to join metal components in jewelry and armor. Rivets, essentially short metal rods hammered through pre-drilled holes and deformed at the ends to secure the connection, allowed for durable assemblies in items such as swords, daggers, and decorative ornaments. This method relied on manual deformation of ductile metals like and alloys, marking an early precedent for pressure-based joining without adhesives or heat fusion. By the , pre-industrial tools including hammers and simple dies facilitated crimping-like processes in applications, particularly for roofing. Artisans used these hand tools to fold and deform the edges of sheets, creating standing seams that interlocked panels for weatherproofing on buildings in regions like and early American colonies. This technique, often performed on-site with mallets and stakes, emphasized precise edge bending to ensure tight joints, predating mechanized production. In the , crimping concepts advanced with the introduction of for , building on Nicolas Appert's 1809 patent for heat-sterilized sealed containers. By the 1820s, adaptations to cans involved forming body seams through mechanical deformation and , enabling of preserved goods for military and civilian use. Concurrently, the 1840s saw the rollout of systems, where wire joints were initially achieved by twisting the ends together and them for conductivity, as seen in early installations along railroads. Early electrical applications of such joining methods appeared in Thomas Edison's laboratory experiments during the 1870s, particularly in telegraph and nascent power systems. As described in Edison's article on telegraph systems, wire connections involved twisting multiple wire strands together—often four or five turns—before and trimming to create reliable connections, supporting innovations like the quadruplex telegraph.

Modern Innovations

Following , the rapid expansion of and automotive industries spurred significant advancements in crimping automation for electrical harnesses. In the late , the need for efficient assembly in applications led to the adoption of crimp terminals in wiring, where solderless connections improved reliability under and environmental stress. By 1949, Sumitomo Electric entered the automotive wiring harness market, leveraging automated crimping to produce standardized harnesses for post-war vehicles, marking the beginning of large-scale industrial adoption. This automation reduced manual labor and enabled consistent quality, with early tools like ratcheting crimpers facilitating in for systems requiring high-density connections. Into the , automotive manufacturers integrated fully automated crimping lines, boosting efficiency in harness assembly for increasingly complex electrical systems in passenger cars and commercial . Material innovations in the late extended crimping to new domains, particularly with the rise of fiber optics and advanced polymers. During the 1980s, as fiber optic networks proliferated for , crimping techniques evolved to secure optical fibers within connectors, such as the SC type developed by NTT for low-loss, reliable terminations in high-speed data transmission. These crimp-style connectors used precision ferrules to align fibers without adhesives, enabling field-installable joins that supported the global rollout of undersea and terrestrial cables. In the 1990s, crimpable polymers like (PEX) transformed systems, where brass or plastic crimp rings created secure, corrosion-resistant fittings for flexible tubing in residential and commercial applications. This innovation simplified installation compared to , with PEX crimp systems gaining widespread use by the mid-1990s due to their flexibility and resistance to freeze-thaw cycles. In the 2010s and beyond, precision methods like laser-assisted and ultrasonic crimping addressed challenges in miniaturization and sensitive materials. Laser-assisted crimping utilizes focused beams to heat and deform connectors selectively, achieving sub-millimeter accuracy for microelectronics without thermal damage to adjacent components, as demonstrated in patents for controlled stent deployment and fiber alignment. Ultrasonic techniques, meanwhile, apply high-frequency vibrations to form solid-state bonds in thin wires and delicate substrates, such as conductive textiles or insulated conductors, minimizing deformation and enabling joins in applications like wearable electronics and battery assemblies. These methods have enhanced reliability in high-vibration environments, with ultrasonic welding outperforming traditional crimps in pull strength for copper-aluminum hybrids. In the 2020s, advancements in automated crimping incorporated AI-driven force monitoring and data analytics for high-volume production of wiring harnesses in electric vehicles, enhancing precision and reducing defects as of 2025. Global standardization efforts in the focused on amid miniaturization trends in and fiber optics. The ISO/IEC 11801 standard, first published in 1995 and revised through the , defined requirements for balanced and optical cabling systems, including crimp-compatible connectors for Category 6A and multimode fibers to support in compact devices. Complementary standards like SAE USCAR21 established performance criteria for automotive crimps, emphasizing pull-out force and conductivity for miniaturized harnesses in electric vehicles. These evolutions ensured crimp joints met , thermal cycling, and size constraints, facilitating the integration of fiber optics in and automotive .

References

  1. https://pmc.ncbi.nlm.nih.gov/articles/PMC12381248/
  2. https://nepp.nasa.gov/files/27631/nstd87394a.pdf
  3. https://www.mouser.com/pdfDocs/Whitepaper_Crimpingtools_EN_WEB.pdf
  4. https://repository.lib.ncsu.edu/server/api/core/bitstreams/5213e201-cade-4771-91ce-c162724720f8/content
  5. https://asmedigitalcollection.asme.org/manufacturingscience/article-abstract/145/2/021007/1145713/Designing-of-a-Field-Shaper-for-Electromagnetic?redirectedFrom=PDF
  6. https://dl.asminternational.org/handbooks/book/chapter-pdf/454522/a0006501.pdf
  7. https://www.te.com/content/dam/te-com/documents/industrial/global/1-1773953-1-terminals-and-splices-whitepaper.pdf
  8. https://nepp.[nasa](/page/NASA).gov/files/27631/nstd87394a.pdf
  9. https://www.fscables.com/sites/admin/plugins/elfinder/files/fscables/other%20pdf/cablecraft_crimp_guide.pdf
  10. https://pdfs.semanticscholar.org/b41c/076d9290c08118703183f4c31b7727e6bd4e.pdf
  11. https://www.doitpoms.ac.uk/tlplib/mechanical_properties/plastic.php
  12. https://mechanicalc.com/reference/mechanical-properties-of-materials
  13. https://www.cnccookbook.com/work-hardening-strain-hardening-machinists-guide/
  14. https://www.nature.com/articles/s41598-021-97498-8
  15. https://www.researchgate.net/publication/43057059_Improved_Crimp-Joining_of_Aluminum_Tubes_onto_Mandrels_with_Undulating_Surfaces
  16. http://timron-inc.com/Brochures_Papers/Contact%20Properties%20of%20Tubular%20Crimp%20Connections_Holm2008.pdf
  17. https://pmc.ncbi.nlm.nih.gov/articles/PMC9763498/
  18. https://eoxs.com/new_blog/understanding-the-different-types-of-crimping-tools-and-machines/
  19. https://www.assemblymag.com/articles/91083-handheld-crimping-tools
  20. https://www.molex.com/content/dam/molex/molex-dot-com/products/automated/en-us/applicationtoolingspecificationpdf/213/213309/2133091200-000.pdf?inline
  21. https://www.te.com/content/dam/te-com/documents/application-tooling/global/at-tooling-overview-1308605.pdf
  22. https://www.maunindustries.com/knowledge-base/what-are-crimping-tools-and-how-are-they-used/
  23. https://www.te.com/content/dam/te-com/documents/appliances/global/machine-applied-terminations-open-barrel-terminals-catalog.pdf
  24. https://jtcopper.com/how-to-choose-copper-materials-for-terminal-connectors.html
  25. https://www.copper.org/publications/newsletters/discover/1996/Ct81/connectors.php
  26. https://www.fscables.com/sites/admin/plugins/elfinder/files/fscables/other%2520pdf/cablecraft_crimp_guide.pdf
  27. https://www.ferrulesdirect.com/blogs/news/understanding-hand-crimpers-a-guide-to-different-crimping-shapes
  28. https://www.rennsteig.us/service/general-info/32-forms-of-crimping
  29. https://www.elecdirect.com/media/specsheets/Terminals-ElecDirect.pdf
  30. https://media.digikey.com/pdf/data%2520sheets/molex%2520pdfs/quality%2520crimp%2520handbook.pdf
  31. https://www.waytekwire.com/aboutus/the-waytek-blog/terminals-and-connectors/insulated-vs-non-insulated-terminals-101
  32. https://www.panduit.com/content/dam/panduit/en/products/media/5/55/455/7455/110187455.pdf
  33. https://www.conwire.com/blog/guide-to-crimp-quality-wire-harnesses-and-cable-assemblies/
  34. https://www.origin-ic.com/blog/identify-and-use-crimp-wire-connectors-for-safe-connections/48102
  35. https://www.allaboutcircuits.com/textbook/direct-current/chpt-12/specific-resistance/
  36. https://hollingsworth.com/technical-resources/technical-data/technical-faqs/
  37. https://cirris.com/crimp-pull-testers-pullout-force-per-wire-size/
  38. https://www.te.com/content/dam/te-com/documents/application-tooling/global/at-wp-crimp-height-meeting-contemporary-quality-standards.pdf
  39. https://wiringharnessnews.com/2421/
  40. https://blog.interpower.com/infopower/crimping-your-conductors-witout-cramping-your-quality
  41. https://hubbellcdn.com/brochure/Connector_Theory_and_Application.pdf
  42. https://www.assemblymag.com/articles/90259-assessing-crimp-quality
  43. https://www.raypcb.com/ipc-620/
  44. https://cloomtech.com/wire-crimping-standards/
  45. https://cetec.co.at/en/what-is-crimping-a-technical-overview-and-its-application-in-cable-production/
  46. https://www.sae.org/standards/content/as7928/
  47. https://www.eeworldonline.com/?p=515606
  48. https://connectorsupplier.com/heavy-duty-terminals-for-automotive-applications/
  49. https://www.mecmesin.com/standard/ul-486a-b
  50. https://www.sae.org/standards/as7928-terminals-lug-splices-conductor-crimp-style-copper-general-specification/
  51. https://monroeaerospace.com/blog/why-ring-terminals-are-color-coded/
  52. https://www.molex.com/en-us/trends-insights/miniaturization/rugged-miniaturized-connectors-report
  53. https://etechcomponents.com/crimping-standards-the-key-to-safe-reliable-connections/
  54. https://www.astm.org/b1029-24.html
  55. https://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf
  56. https://pexuniverse.com/pex-copper-crimp-rings
  57. https://www.plasticpipe.org/PowerCommunications/BuildingConstruction/PEX.aspx
  58. https://www.homedepot.com/c/ab/copper-press-fittings-vs-solder/9ba683603be9fa5395fab9018c86136c
  59. https://www.astm.org/f0876-23.html
  60. https://artbeads.com/blog/crimp-tubes-and-crimp-beads/
  61. https://www.kernowcraft.com/jewellery-making-tips/beading-and-threading-techniques-and-advice/how-to-use-crimps
  62. https://softflexcompany.com/beading-blog/5-techniques-every-beader-should-know/
  63. https://www.gemsociety.org/article/jewelry-metals-overview/
  64. https://bracelets.nl/Blogs/bracelet/basic-jewelry-making-techniques%253A-how-do-crimp-beads-and-crimp-bead-covers-work
  65. https://blog.mestekmachinery.com/news-and-updates/the-methods-of-making-duct-locks
  66. https://mepacademy.com/sheet-metal-seams/
  67. https://mepacademy.com/sheet-metal-joints/
  68. https://www.achrnews.com/articles/164712-a-guide-to-sheet-metal-clinching-for-hvac-contractors
  69. https://www.conklinmetal.com/blog/pittsburgh-seam-small-vs-large/
  70. https://www.fda.gov/media/183739/download
  71. https://industrialphysics.com/knowledgebase/articles/double-seaming-process-guide/
  72. https://www.levapack.com/double-seaming-guide/
  73. https://www.kingarthurbaking.com/videos/bake-it-better-with-kye/how-to-crimp-pie-crust
  74. https://www.bonappetit.com/test-kitchen/primers/article/how-to-shape-fill-ravioli
  75. https://meatscience.org/docs/default-source/publications-resources/rmc/2013/reciprocation-2013---kohl-schrader.pdf?sfvrsn=2
  76. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-113/subpart-D/section-113.60
  77. https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/inspection-guides/guide-inspections-low-acid-canned-food-manufacturers-part-3
  78. https://www.nal.usda.gov/exhibits/ipd/canning/exhibits/show/equipment/tin-cans
  79. https://nij.ojp.gov/nij-hosted-online-training-courses/firearms-examiner-training/module-05/crimping
  80. https://nij.ojp.gov/nij-hosted-online-training-courses/firearms-examiner-training/module-03/cartridge-cases
  81. https://americanhandgunner.com/shooting-iron/tapers-and-rolls/
  82. https://gundigest.com/more/how-to/crimp-styles-uses
  83. https://gundigest.com/gear-ammo/reloading/crimping-rifle-accuracy
  84. https://saami.org/technical-information/cartridge-chamber-drawings/
  85. https://ultimatereloader.com/2023/04/14/basic-rifle-reloading-5-bullet-seating-crimping/
  86. https://www.marxists.org/archive/childe/1930/bronzeage/ch02.htm
  87. https://qualimet.ca/industry-resource/the-history-of-metal-joining-and-welding/
  88. https://www.nps.gov/orgs/1739/upload/preservation-brief-04-roofing.pdf
  89. https://www.islandmetals.com/history-of-metal-roofing.html
  90. https://www.britannica.com/topic/canning-food-processing
  91. https://www.britannica.com/technology/telegraph
  92. http://www.telegraph-history.org/edison/appletons/index.html
  93. https://sumitomoelectric.com/id/dna/v07
  94. https://www.tti.com/content/ttiinc/en/resources/blog/mil-dtl-38999-connectors-about.html
  95. https://www.fundinguniverse.com/company-histories/amp-incorporated-history/
  96. https://orbray.com/magazine_en/archives/158
  97. https://www.ifanpiping.com/info/historical-development-of-pex-compression-fitt-98316179.html
  98. https://patents.google.com/patent/US20050119720A1/en
  99. https://pmc.ncbi.nlm.nih.gov/articles/PMC8510271/
  100. https://pmc.ncbi.nlm.nih.gov/articles/PMC11509339/
  101. https://www.archivemarketresearch.com/reports/electric-wire-crimping-machine-179599
  102. https://cdn.standards.iteh.ai/samples/33871/79c51b41155c4a278620246aaa5ee2e3/ISO-IEC-11801-2000.pdf
  103. https://www.sae.org/standards/uscar21-performance-specification-cable-terminal-electrical-crimps
  104. https://www.sae.org/standards/as39029-contacts-electrical-connector-general-specification
Add your contribution
Related Hubs
User Avatar
No comments yet.