Home | Phenolic Flat Washers - Hard, Heat-Resistant Insulating Washers

Phenolic Flat Washers - Hard, Heat-Resistant Insulating Washers

Phenolic flat washers are made from thermoset phenolic resin, offering excellent electrical insulation, hardness, and heat resistance-making them a reliable non-metallic washer for electrical equipment, circuit boards, and industrial applications with moderate temperature exposure. Superior Washer & Gasket Corp produces phenolic washers in standard and custom sizes.

As an ISO 9001:2015 certified specialty washer manufacturer, we supply phenolic washers alongside fiberglass, Kapton, mica, and other high-performance insulating washers-all made in the U.S.A. to your precise OD, ID, and thickness requirements.

  • Thermoset phenolic for hardness and electrical insulation
  • Good heat resistance for industrial applications
  • Standard and custom phenolic washer configurations
  • ISO 9001:2015 certified manufacturing
  • Made in the U.S.A.

Showing 1–50 of 243 products

SKU ID OD Thickness Material ID TOL OD TOL Quantity

440-10-016

ID 0.055
OD 0.125
Thickness 0.016
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-100-031

ID 0.171
OD 0.25
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-101-031

ID 0.171
OD 0.281
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-102-031

ID 0.171
OD 0.312
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-103-031

ID 0.171
OD 0.343
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-104-031

ID 0.171
OD 0.375
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-105-062

ID 0.171
OD 0.437
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-106-031

ID 0.171
OD 0.5
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-106M-031

ID 0.177
OD 0.5
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-107-062

ID 0.171
OD 0.562
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-108-031

ID 0.171
OD 0.625
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-109-062

ID 0.171
OD 0.735
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-11-016

ID 0.063
OD 0.187
Thickness 0.016
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-110-016

ID 0.187
OD 0.312
Thickness 0.016
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-111-031

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

440-112-062

ID 0.187
OD 0.437
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-113-031

ID 0.187
OD 0.5
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-114-062

ID 0.187
OD 0.531
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-115-016

ID 0.187
OD 0.625
Thickness 0.016
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-116-031

ID 0.187
OD 1.0
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-117-062

ID 0.187
OD 1.781
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-118-031

ID 0.194
OD 0.312
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-119-062

ID 0.194
OD 0.343
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-12-016

ID 0.063
OD 0.218
Thickness 0.016
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-120-031

ID 0.194
OD 0.375
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-121-062

ID 0.194
OD 0.437
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-122-062

ID 0.194
OD 0.5
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-123-031

ID 0.194
OD 0.562
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-124-062

ID 0.194
OD 0.625
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-125-031

ID 0.194
OD 0.687
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-126-062

ID 0.194
OD 0.75
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-127-031

ID 0.2
OD 0.375
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-128-031

ID 0.2
OD 0.437
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-129-031

ID 0.2
OD 0.5
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-13-031

ID 0.063
OD 0.25
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-130-062

ID 0.2
OD 0.562
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-131-063

ID 0.2
OD 0.625
Thickness 0.063
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-132-031

ID 0.219
OD 0.312
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-133-031

ID 0.219
OD 0.375
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-134-031

ID 0.219
OD 0.437
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-135-062

ID 0.219
OD 0.5
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-136-062

ID 0.219
OD 0.625
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-137-031

ID 0.225
OD 0.375
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-138-031

ID 0.225
OD 0.5
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-139-031

ID 0.253
OD 0.43
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-14-031

ID 0.063
OD 0.281
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-140-031

ID 0.253
OD 0.437
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-141-031

ID 0.253
OD 0.406
Thickness 0.031
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

440-142-062

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

440-143-062

ID 0.253
OD 0.62
Thickness 0.062
Material Phenolic
ID TOL +-.005
OD TOL +-.005
Quantity

Phenolic Flat Washer Frequently Asked Questions

Below are answers to some of the most common questions about phenolic flat washers.

What are phenolic flat washers?
Phenolic flat washers are manufactured from phenol-formaldehyde resin laminate (Bakelite or equivalent), one of the oldest and most established electrical insulating materials. Phenolic is available in paper-base (XX, XXX, XXXP), cotton-base (C, CE, LE), and glass-base (G10) grades, each offering different balances of electrical, mechanical, and thermal properties.

What are phenolic washers used for?
Phenolic washers are used as electrical insulators in switchgear, relay panels, transformers, motors, and terminal blocks. They are also used as mechanical spacers in assemblies where a rigid, non-conductive washer is required. Phenolic is harder and more rigid than most thermoplastic washer materials, which makes it suitable for high-compression applications.

What phenolic grades do you stock?
Superior Washer manufactures phenolic flat washers in XX, XXX, and CE grades depending on the required electrical and mechanical properties. Contact us to specify the grade needed for your application.

Can you make custom phenolic flat washers?
Yes. We manufacture custom phenolic washers to your OD, ID, and thickness specifications. Contact us via the Quick Quote form or by phone.

Are your phenolic flat washers made in the USA?
Yes. All phenolic flat washers are manufactured in the United States under our ISO 9001:2015 certified Quality Management System. Material certifications are available upon request.

Phenolic is one of several rigid insulating materials we manufacture. View our complete flat washers lineup to compare all the options available.