top of page

Varglas 240 Silicone Rubber Sleeving

Varglas 240 Silicone Rubber sleevings are produced by coating braided fiberglass with a specially formulated, proprietary silicone rubber that exhibits exceptional high-temperature properties. In addition to its flexibility, toughness and abrasion resistance, Varglas 240 Silicone Rubber sleevings provides superior thermal protection and flame resistance with a higher dielectric capability at less weight than previously available. Its ability to meet a Class 240°C rating, combined with a brittleness temperature of -80°C, makes it an ideal choice for applications that require outstanding physical and electrical insulation properties throughout a wide operating temperature range.

Class: 240 S (-80°C to +240°C) (-112°F to +464°F)

Dielectric Strength Grade: A-1


Varglas 240 Silicone Rubber sleevings conforms to and is listed on the qualified products list for, MIL-l-3190/9, latest revision (Grade A); and exceeds the requirements of UL 1441, Table 19.8; NEMA TF-1, Type 5; and ASTM-D372.

Under the Component Program of Underwriters Laboratories, Grade A Varglas 240 Silicone Rubber is recognized for 240°C, 600 volt service and complies with VW-1 flammability requirements under UL File #E63450. CSA International certifies the use of Grade A for 240°C, 600 volt service and VW-1 flammability under CSA File #LR58486.


Varglas 240 Silicone Rubber sleevings are suitable for industrial applications such as motors, generators, transformers and engines; where superior dielectric protection at elevated temperatures of 240°C is critical. In addition to automotive engines, Varglas 240 Silicone Rubber flame resistances and wide-operating temperature ranges make it particularly well suited for aircraft engines and other aerospace applications; where it satisfies electrical and thermal barrier requirements while providing the added benefit of lighter weight.


AWG #24 through 2” l.D. Other sizes subject to inquiry.

Standard Colors

Red oxide and black only.

Standard Packaging

Coils, spools or 36” lengths at manufacturer’s option, unless otherwise specified. There is no cutting charge for 36” lengths, but lengths other than 36” are subject to cutting charges.
Sizes over 1” l.D. are generally supplied in 36” lengths.

Varglas 240 Silicone Rubber: List
bottom of page