Showing 1–50 of 220 products
Fiber Flat Washers - Non-Conductive Hard Fiber Washers
Fiber flat washers made from hard vulcanized fiber provide electrical insulation, moderate chemical resistance, and lightweight performance for industrial, electrical, and commercial applications. Superior Washer & Gasket Corp manufactures hard fiber washers in standard and custom sizes as a cost-effective non-metallic washer solution.
Our ISO 9001:2015 certified specialty washer capabilities include hard fiber, felt, fiberglass, and phenolic washers in a wide range of thicknesses and OD/ID dimensions. Custom fiber washers are produced to your exact specifications and made in the U.S.A. with fast lead times.
- Hard vulcanized fiber for electrical insulation
- Lightweight and cost-effective non-metallic option
- Standard and custom fiber washer sizes
- ISO 9001:2015 certified quality management
- Made in the U.S.A.
Description
Fiber Flat Washer Frequently Asked Questions
Below are answers to some of the most common questions about fiber flat washers.
What are fiber flat washers?
Fiber flat washers are manufactured from vulcanized fiber, a dense, rigid material made from chemically treated cellulose (cotton or wood pulp). Vulcanized fiber is non-conductive, non-magnetic, lightweight, and tough, and has been used as an electrical and mechanical insulating material in industrial applications for over a century.
What are fiber washers used for?
Fiber washers are commonly used as electrical insulators between metal components, as cushioning washers to prevent surface damage, and in applications requiring a non-conductive, non-metallic washer that is tougher than plastic but more economical than engineered resins. They are used in switchgear, electrical panels, automotive assemblies, and general industrial fastener applications.
How does vulcanized fiber differ from plastic washer materials?
Vulcanized fiber is a natural cellulose-based material, not a synthetic polymer. It is generally denser and tougher than many plastics, with good machinability and excellent dielectric properties. It absorbs more moisture than synthetic plastics, which can cause dimensional changes in high-humidity environments, but it remains a cost-effective choice for many electrical insulation applications.
Can you make custom fiber flat washers?
Yes. Superior Washer manufactures custom fiber washers to your OD, ID, and thickness specifications. Contact us via the Quick Quote form or by phone.
Are your fiber flat washers made in the USA?
Yes. All fiber flat washers are manufactured in the United States under our ISO 9001:2015 certified Quality Management System. Material certifications are available upon request.
Vulcanized fiber is one of many non-metal options we produce. Browse our full range of flat washers to compare materials and find the best fit for your application.

