Silicone vs Teflon - Which High Temperature Wire is Better?

Silicone vs Teflon – Which High Temperature Wire is Better?

Silicone rubber and Teflon are among the most commonly used materials for wire and cable insulation designed for service at high temperatures or under other severe conditions that degrade the electrical or physical properties of other materials. The number of such applications is increasing steadily. 

Because of their mutual superiority to other materials in such applications, comparisons between Silicone vs Teflon are inevitable. We discuss their comparison in detail to help you decide.

Silicone vs Teflon – Installation and Handling

Ease of Stripping

Silicone – Silicone rubber does not have to be cut through entirely for easy stripping, thus lessening the danger of conductor damage.

Teflon – Because of the inherent toughness of the insulation, Teflon coated wire is not as easy to strip. 


Silicone – Has excellent flexibility at room temperatures and maintains this at temperatures below 100 degrees Fahrenheit.

Teflon – Is inherently a relatively stiff material. It reduces the flexibility of conductors and makes them more challenging to handle. A degree of flexibility is maintained at temperatures below 100 degrees Fahrenheit.


Unlike conventional low melting point thermoplastic materials, neither silicone rubber nor Teflon will melt nor shrink excessively during soldering operations. This feature is critical during the wiring of intricate control panels where the slip of a soldering iron may ruin adjacent installations.

Silicone vs Teflon - Which High Temperature Wire is Better?Silicone vs Teflon – Service Characteristics

Service Temperature Range

Both Teflon and silicone wires perform well over the temperature range from -100 to 500 degrees Fahrenheit. The two materials have excellent high-temperature stability and can withstand months of continuous exposure to heat.

However, at prolonged high temperatures, ageing silicone rubber will result in gradual hardening, shrinkage and embrittlement. Teflon will decompose, giving off fluorine-containing materials. Adequate ventilation is recommended when using Teflon at temperatures above 400 degrees Fahrenheit to remove harmful vapours.

Overload reliability

Under high overload conditions, conductors become extremely hot and cause decomposition of Teflon insulation, with toxic fumes’ evolution. Under similar conditions, silicone wires may become brittle, but if protected by an outer glass braid, they will retain insulating properties.

Flame resistance

Silicone wires are slow-burning. Its ash is mainly silicone dioxide, a suitable dielectric. Teflon wires are non-flammable but will decompose in a direct flame and can give off toxic fumes

Cold flow

One of Teflon’s most significant drawbacks is its tendency to flow under pressure over some time at almost any pressure. This is due to its fundamentally plastic rather than elastomeric nature. Although some return does occur upon removing the exerted force, much of the deformation is permanent. Silicone wires, being truly elastomeric and exhibiting excellent compression set resistance over a wide temperature range, has far less tendency to cold flow.

Cut-through resistance

In the standard thumbnail test, Teflon appears to be appreciably tougher than silicone rubber. Teflon wires are not readily cut by tight laces, but its low cold flow characteristics over some time make it virtually impossible to keep lacing tight. Newer silicone wiring with better physical properties than its earlier counterparts are tough enough to withstand lacing cut-through and will not promote loosening due to cold flow.

Silicone vs Teflon – Electrical Characteristics

Fundamental Properties

Teflon Wire has outstanding electrical characteristics. Exceptional stability in dielectric constant and power factor makes it particularly applicable for high-frequency applications. 

The electricals of silicone rubber will vary with the composition. Electrical grade compounds are outstanding in the four fundamental properties of volume resistivity, dielectric strength, dielectric constant and power factor. Most application requirements can be met without difficulty.

Dialectric Fatigue

Short-time dielectric strength values for Teflon wires are higher than values for Silicone wires. However, Teflon will erode and exhibit dielectric fatigue when exposed to more extended periods at moderate electric stress. Silicone wires are far less apt to display this characteristic.

Arc Resistance

Both silicone wires and Teflon wires have good arc resistance and will withstand standard tests for over 200 seconds. No carbon path is formed regardless of temperature.

Corona Resistance

Silicone wires’ resistance to corona is outstanding among all elastomers, approaching that of mica. Like other organic materials, Teflon wires are eroded by corona, and special designs are required to minimize corona at high voltages.

Teflon Wiring Applications

Teflon has a lot of different applications like general hook-up wire, high temperature, or military. Teflon wire’s durability is the most wanted factor about these cables as they’re able to withstand temperatures reaching up to 450 degrees celsius. Usually, Teflon wiring is used in applications that need corrosion resistance, heat resistance, wear or friction resistance. Some applications that Teflon cables are relied on for are robotics, automation, navigation, air conditioning, and automobiles. 

Silicone Wiring Applications

Because silicone is an insulator, there are a variety of special features that help this cable fulfill its requirements for specific applications. Silicone wires are flexible in high temperatures and this is just one of their unique characteristics. Increased flexibility is why SGI cables can be used as hook-up wiring in high-temperature applications. It can fit in small locations and can survive moderate handling that no other cables or wires can. 

Silicon vs Teflon – Which High-Temperature Wire is Better?

Finally, both silicone and Teflon cables are best for a wide variety of applications. May it be a general-purpose hook-up wire or a high resistance wire that is subject to consistent handling. You should understand what purpose your application needs because neither cable is better overall. Both have their advantages and disadvantages. 

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