Key Takeaways
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Vinyl terminals are the least expensive insulated option but are not sealed, making them prone to corrosion and wire pull-out.
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Nylon terminals are more flexible than vinyl, more chemical resistant, and can be double-crimped for added tensile strength and strain relief.
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Nylon terminals are semi-translucent, which allows you to visually confirm that the wire is fully seated before crimping.
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Neither vinyl nor nylon terminals are sealed connections. Heat shrink terminals provide a sealed option for connections exposed to the elements.
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Royal Brass and Hose carries nylon, vinyl, heat shrink, and non-insulated terminal types, with assortment boxes available at many locations.
Choosing the wrong wire terminal insulation type leads to corrosion at the connection point, wires that pull out under tension, or a crimp that is difficult to inspect after installation. Electrical connectors are critical to the function of vehicles, industrial equipment, and electrical devices. This guide compares vinyl and nylon insulated terminals so you can match the right type to your application. Heat shrink and non-insulated terminals also exist but are not covered here.
Nylon terminals are more popular and perform better than vinyl, but are not as protective as heat shrink terminals for connections exposed to the elements.
What Are the Advantages and Limitations of Vinyl Insulated Terminals?
Vinyl insulated terminals use a polyvinyl chloride (PVC) sleeve over the crimp barrel. They are widely available and typically the least expensive insulated option.
Advantages:
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Easy crimp installation
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Usually the least expensive insulated option
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Wide selection of types and sizes
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Commonly available
Limitations:
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Not a sealed connection. Prone to moisture ingress and corrosion.
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Wires can pull out under tension
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Crimp area is not visible through the insulation, making it difficult to inspect connection quality before installation
What Are the Advantages and Limitations of Nylon Insulated Terminals?
Nylon insulated terminals use a nylon sleeve over the crimp barrel. Nylon is more flexible than vinyl and resists cracking in environments where vinyl would become brittle. Nylon terminals are typically designed for double crimping, which delivers additional tensile strength and strain relief against wire pull-out.
Advantages:
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Easy crimp installation
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More flexible than vinyl and less prone to cracking
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More chemical resistant than vinyl
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Can be double-crimped for a stronger connection with better strain relief
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Semi-translucent insulation allows visual confirmation that the wire is fully seated before crimping
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Wide selection of types and sizes
Limitations:
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Wires can be prone to pulling out if not double-crimped properly
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More expensive than vinyl
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Not a sealed connection. Prone to corrosion in high-moisture or outdoor environments.
Royal Brass and Hose carries a full selection of wire terminals. Shop Electrical Wire Terminals.
We offer a choice of nylon, vinyl, heat shrink, and non-insulated types at many of our locations, with assortment boxes available.
Need Help with Your Electrical Connector Selection?
Royal Brass and Hose carries nylon, vinyl, heat shrink, and non-insulated wire terminals at many locations, with assortment boxes available for stocking a range of sizes. Contact a location near you for availability and application guidance.
Contact us today or call us at 800-669-9650 for help selecting the right wire terminals for your application.
We have 11 locations across the Southeast and Midwest, including Knoxville, TN; Marietta, GA; Orlando, FL; Charlotte, NC; Little Rock, AR; Fort Worth, TX; Benton, IL; Madisonville, KY; Princeton, WV; Birmingham, AL; and Calvert City, KY.
Frequently Asked Questions
Choose nylon when flexibility, chemical resistance, or connection visibility are priorities. The semi-translucent insulation allows you to confirm the wire is fully seated before crimping, reducing the chance of a bad connection. For any application where the wire may be pulled or flexed, nylon with a double crimp provides better strain relief than vinyl.
Neither vinyl nor nylon terminals are sealed connections. Both are prone to corrosion when exposed to moisture over time. For outdoor installations or connections exposed to the elements, heat shrink terminals with an adhesive-lined sleeve provide a sealed, corrosion-resistant connection.
A double crimp applies separate crimps to the wire conductor and the wire insulation. The conductor crimp creates the electrical connection. The insulation crimp provides strain relief, preventing the wire from pulling out of the barrel under tension. Nylon terminals are typically designed to accept a double crimp; most vinyl terminals are not.
Match the terminal to the wire gauge. Most insulated terminals are color-coded by gauge range: red for 22-18 AWG, blue for 16-14 AWG, and yellow for 12-10 AWG. Confirm the wire gauge before selecting a terminal. Using a terminal sized for a heavier gauge than your wire will result in a loose crimp and a poor connection.
Insulated terminals (vinyl, nylon, heat shrink) include a protective sleeve over the crimp barrel that prevents accidental shorts and reduces exposure to moisture. Non-insulated terminals have a bare metal crimp barrel with no sleeve. They are used in applications where the connection will be covered separately, in high-temperature environments where insulation would degrade, or where space constraints prevent the use of an insulated terminal.
