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.

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Showing 1–50 of 220 products

Fiber Flat Washers - Non-Conductive Hard Fiber Washers

SKU ID OD Thickness Material ID TOL OD TOL Quantity Actions

330-10-016

ID 0.045
OD 0.125
Thickness 0.016
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-100-031

ID 0.178
OD 0.437
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-101-062

ID 0.178
OD 0.5
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-102-031

ID 0.187
OD 0.312
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-103-015

ID 0.187
OD 0.375
Thickness 0.015
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-103-031

ID 0.187
OD 0.375
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-104-062

ID 0.187
OD 0.406
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-105-031

ID 0.187
OD 0.437
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-106-062

ID 0.187
OD 0.5
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-107-062

ID 0.196
OD 0.375
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-108-031

ID 0.196
OD 0.406
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-109-062

ID 0.196
OD 0.562
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-11-016

ID 0.045
OD 0.187
Thickness 0.016
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-110-031

ID 0.196
OD 0.625
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-111-031

ID 0.203
OD 0.375
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-111-061

ID 0.203
OD 0.375
Thickness 0.061
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-112-020

ID 0.203
OD 0.39
Thickness 0.02
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-113-062

ID 0.203
OD 0.406
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-114-062

ID 0.203
OD 0.437
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-115-031

ID 0.203
OD 0.5
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-116-031

ID 0.203
OD 0.625
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-117-031

ID 0.203
OD 0.75
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-118-016

ID 0.218
OD 0.375
Thickness 0.016
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-119-031

ID 0.218
OD 0.437
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-12-016

ID 0.045
OD 0.25
Thickness 0.016
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-120-062

ID 0.218
OD 0.468
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-121-016

ID 0.218
OD 0.5
Thickness 0.016
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-122-031

ID 0.227
OD 0.375
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-123-031

ID 0.227
OD 0.406
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-124-031

ID 0.227
OD 0.437
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-125-031

ID 0.227
OD 0.5
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-126-062

ID 0.227
OD 0.562
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-127-062

ID 0.227
OD 0.625
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-128-031

ID 0.253
OD 0.375
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-129-062

ID 0.253
OD 0.437
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-13-016

ID 0.062
OD 0.125
Thickness 0.016
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-130-062

ID 0.253
OD 0.5
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-131-016

ID 0.253
OD 0.531
Thickness 0.016
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-132-031

ID 0.253
OD 0.562
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-133-031

ID 0.253
OD 0.593
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-134-031

ID 0.253
OD 0.625
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-135-062

ID 0.253
OD 0.75
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-136-062

ID 0.261
OD 0.625
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-137-062

ID 0.261
OD 0.687
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-138-031

ID 0.261
OD 0.75
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-139-062

ID 0.261
OD 0.875
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-14-032

ID 0.062
OD 0.156
Thickness 0.032
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-140-031

ID 0.265
OD 0.5
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-141-062

ID 0.281
OD 0.5
Thickness 0.062
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

330-142-031

ID 0.281
OD 0.562
Thickness 0.031
Material Fiber
ID TOL +-.005
OD TOL +-.005
Quantity

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.