Terminal crimping is a critical process in creating secure, long-lasting electrical connections. Understanding its theory and performance helps ensure safety, conductivity, and reliability in electrical systems.
What Is Terminal Crimping?
Terminal crimping refers to the process of mechanically compressing a terminal onto a wire to create a strong electrical and mechanical bond. It is widely used in automotive, industrial, and electronic applications.
Wire Construction and AWG Standards
Wires consist of a conductive core (solid or stranded) and insulation. Wire sizes follow the American Wire Gauge (AWG) system. Common sizes include:
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24AWG (small)
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18AWG (medium)
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12AWG (large)
A key concept is CMA (Circular Mil Area), used to calculate the cross-sectional area of conductors:
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Single-core wire: CMA = D²
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Stranded wire: CMA = D² × N
(D = wire diameter, N = number of strands)
Example:
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D = 0.162 → CMA = 26,244 → equivalent to 6AWG
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D = 0.0152, N = 7 → CMA = 1,575 → equivalent to 18AWG
Types of Crimp Terminals
Terminal design varies based on application and wire type. Common terminal types include:
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Open-barrel terminals
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Closed-barrel terminals, such as:
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PIDG terminals (triangular insulation crimp, square/crescent conductor crimp)
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FASTON terminals (D-shaped crimp)
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Terminal Materials
High-performance terminals are often made of:
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Nickel
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Bronze
These metals provide low resistance, high hardness, and temperature resistance, making them ideal for harsh environments.
Crimping Performance and Electrical Integrity
Crimp quality is influenced by pressure, crimp height, and wire contact:
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Increased pressure → lower crimp height
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Lower crimp height → stronger mechanical bond and better electrical conductivity
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Proper crimping reduces resistance and voltage drop
Key takeaway: Correct crimping ensures long-term reliability and minimizes risk of failure in electrical systems.