Hard Fiber Insulation | McMaster-Carr

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178 Products

Hard Fiber Washers

The least likely to scratch or mar delicate mounting surfaces, these washers are made of hardened cotton fiber. They are also naturally nonconductive, so they are a great choice for insulating nuts and screws to prevent unintended charges. However, fiber washers will break down faster than other washers and will need to be replaced more often.

For Screw Size	ID	OD	Thk.	Specs. Met	Color	Pkg. Qty.		Pkg.
No. 2	0.094"	0.250"	0.010" to 0.020"	—	Black	100	96100A110	000000
No. 2	0.094"	0.250"	0.014" to 0.016"	—	Gray	100	90089A290	0000
No. 2	0.094"	0.250"	0.028" to 0.034"	—	Red	100	95601A290	0000
No. 4	0.125"	0.250"	0.014" to 0.016"	—	Gray	100	90089A295	0000
No. 4	0.125"	0.250"	0.028" to 0.034"	—	Red	100	95601A295	0000
No. 4	0.125"	0.312"	0.010" to 0.020"	—	Black	100	96100A115	00000
No. 4	0.126"	0.375"	0.035" to 0.045"	—	Black	10	90132A110	00000
No. 5	0.141"	0.312"	0.035" to 0.045"	—	Black	10	90132A120	00000
No. 6	0.145"	0.375"	0.026" to 0.036"	—	Black	100	96100A120	00000
No. 6	0.156"	0.312"	0.014" to 0.016"	—	Gray	100	90089A300	0000
No. 6	0.156"	0.312"	0.028" to 0.034"	—	Red	100	95601A300	0000
No. 8	0.172"	0.375"	0.026" to 0.036"	—	Black	100	96100A125	00000
No. 8	0.188"	0.375"	0.014" to 0.016"	—	Gray	100	90089A305	0000
No. 8	0.188"	0.375"	0.028" to 0.034"	—	Red	100	95601A305	0000
No. 8	0.188"	0.438"	0.035" to 0.045"	—	Black	10	90132A130	0000
No. 10	0.203"	0.375"	0.042" to 0.052"	—	Black	100	96100A137	00000
No. 10	0.203"	0.438"	0.042" to 0.052"	—	Black	100	96100A130	00000
No. 10	0.203"	0.500"	0.035" to 0.045"	—	Black	10	90132A140	0000
No. 12	0.234"	0.500"	0.042" to 0.052"	—	Black	50	96100A135	0000
1/4"	0.250"	0.375"	0.014" to 0.016"	—	Gray	100	90089A310	0000
1/4"	0.250"	0.375"	0.028" to 0.034"	—	Red	100	95601A310	0000
1/4"	0.250"	0.500"	0.014" to 0.016"	—	Gray	100	90089A315	0000
1/4"	0.250"	0.500"	0.028" to 0.034"	—	Red	100	95601A315	0000
1/4"	0.281"	0.625"	0.057" to 0.067"	ASME B18.21.1	Black	25	96100A140	00000
5/16"	0.312"	0.438"	0.014" to 0.016"	—	Gray	100	90089A320	0000
5/16"	0.312"	0.438"	0.028" to 0.034"	—	Red	100	95601A320	0000
5/16"	0.312"	0.562"	0.014" to 0.016"	—	Gray	100	90089A325	0000
5/16"	0.312"	0.562"	0.028" to 0.034"	—	Red	100	95601A325	0000
5/16"	0.325"	0.688"	0.057" to 0.067"	—	Black	100	96100A142	00000
3/8"	0.375"	0.500"	0.014" to 0.016"	—	Gray	100	90089A330	0000
3/8"	0.375"	0.500"	0.028" to 0.034"	—	Red	100	95601A330	0000
3/8"	0.375"	0.625"	0.014" to 0.016"	—	Gray	100	90089A335	0000
3/8"	0.375"	0.625"	0.028" to 0.034"	—	Red	100	95601A335	0000
3/8"	0.375"	2.250"	0.110" to 0.140"	—	Gray	10	90132A552	00000
3/8"	0.406"	0.875"	0.086" to 0.100"	—	Black	25	96100A145	00000
7/16"	0.438"	0.625"	0.014" to 0.016"	—	Gray	50	90089A340	0000
7/16"	0.438"	0.625"	0.028" to 0.034"	—	Red	100	95601A340	0000
1/2"	0.500"	0.625"	0.028" to 0.034"	—	Red	100	95601A345	0000
1/2"	0.500"	0.688"	0.014" to 0.016"	—	Gray	100	90089A350	0000
1/2"	0.500"	0.688"	0.028" to 0.034"	—	Red	100	95601A350	0000
1/2"	0.500"	0.750"	0.014" to 0.016"	—	Gray	100	90089A355	0000
1/2"	0.500"	0.750"	0.028" to 0.034"	—	Red	100	95601A355	0000
1/2"	0.500"	2.250"	0.110" to 0.140"	—	Gray	10	90132A553	00000
1/2"	0.531"	1.000"	0.086" to 0.100"	—	Black	25	96100A150	00000
9/16"	0.562"	0.812"	0.014" to 0.016"	—	Gray	100	90089A360	00000
9/16"	0.562"	0.812"	0.028" to 0.034"	—	Red	100	95601A360	0000
5/8"	0.625"	0.750"	0.028" to 0.034"	—	Red	100	95601A365	0000
5/8"	0.625"	0.875"	0.014" to 0.016"	—	Gray	50	90089A375	0000
5/8"	0.625"	0.875"	0.028" to 0.034"	—	Red	100	95601A375	0000
5/8"	0.625"	2.250"	0.110" to 0.140"	—	Gray	10	90132A554	00000
5/8"	0.645"	1.063"	0.086" to 0.100"	—	Black	25	96100A152	00000
5/8"	0.656"	1.312"	0.086" to 0.100"	—	Black	5	90132A150	0000
5/8"	0.688"	0.938"	0.028" to 0.034"	—	Red	100	95601A390	0000
3/4"	0.750"	1.000"	0.014" to 0.016"	—	Gray	100	90089A395	0000
3/4"	0.750"	1.000"	0.028" to 0.034"	—	Red	100	95601A395	0000
3/4"	0.750"	1.063"	0.028" to 0.034"	—	Red	100	95601A400	0000
3/4"	0.750"	2.250"	0.110" to 0.140"	—	Gray	10	90132A555	00000
3/4"	0.810"	1.125"	0.110" to 0.140"	—	Black	10	96100A155	00000
3/4"	0.812"	1.125"	0.014" to 0.016"	—	Gray	100	90089A405	0000
3/4"	0.812"	1.125"	0.028" to 0.034"	—	Red	50	95601A405	0000
7/8"	0.875"	1.188"	0.014" to 0.016"	—	Gray	100	90089A410	0000
7/8"	0.875"	1.188"	0.028" to 0.034"	—	Red	100	95601A410	00000
7/8"	0.875"	2.250"	0.110" to 0.140"	—	Gray	10	90132A556	00000
7/8"	0.930"	1.250"	0.110" to 0.140"	—	Black	10	96100A157	00000
7/8"	0.938"	1.250"	0.028" to 0.034"	—	Red	50	95601A415	0000
1"	1.000"	1.250"	0.014" to 0.016"	—	Gray	100	90089A420	0000
1"	1.000"	1.250"	0.028" to 0.034"	—	Red	100	95601A420	00000
1"	1.000"	2.250"	0.110" to 0.140"	—	Gray	10	90132A557	00000
1"	1.031"	1.312"	0.014" to 0.016"	—	Gray	50	90089A425	00000
1"	1.031"	1.312"	0.028" to 0.034"	—	Red	50	95601A425	0000
1"	1.125"	2.000"	0.110" to 0.140"	—	Black	10	96100A160	00000
1 1/8"	1.188"	1.562"	0.028" to 0.034"	—	Red	100	95601A430	00000
1 1/4"	1.250"	1.625"	0.028" to 0.034"	—	Red	50	95601A435	00000
1 1/4"	1.312"	2.125"	0.110" to 0.140"	—	Black	5	96100A170	00000
M1.2	1.3 mm	3.8 mm	0.1 mm to 0.4 mm	DIN 125	Black	10	95225A111	00000
M1.4	1.5 mm	3.8 mm	0.1 mm to 0.4 mm	DIN 125	Black	10	95225A112	00000
M1.6	1.7 mm	3.9 mm	0.1 mm to 0.4 mm	DIN 125	Black	10	95225A113	00000
M2	2.3 mm	5 mm	0.3 mm to 0.5 mm	DIN 125	Black	25	95225A210	00000
M2.5	2.7 mm	6.5 mm	0.4 mm to 0.6 mm	DIN 125	Black	100	95225A310	00000
M3	3.2 mm	7 mm	0.4 mm to 0.6 mm	DIN 125	Black	100	95225A315	00000
M3.5	3.7 mm	7.8 mm	0.4 mm to 0.6 mm	DIN 125	Black	10	95225A114	00000
M4	4.3 mm	9 mm	0.7 mm to 0.9 mm	DIN 125	Black	100	95225A320	00000
M6	6.4 mm	12.5 mm	1.4 mm to 1.7 mm	DIN 125	Black	50	95225A325	0000
M7	7.4 mm	13.8 mm	1.4 mm to 1.7 mm	DIN 125	Black	10	95225A115	00000
M8	8.4 mm	17 mm	1.4 mm to 1.7 mm	DIN 125	Black	50	95225A330	0000
M10	10.5 mm	21 mm	1.8 mm to 2.2 mm	DIN 125	Black	50	95225A335	00000
M12	13 mm	24 mm	2.1 mm to 2.5 mm	DIN 125	Black	50	95225A340	00000
M16	17 mm	30 mm	2.1 mm to 2.5 mm	DIN 125	Black	25	95225A345	0000
M20	21 mm	37 mm	2.1 mm to 2.5 mm	DIN 125	Black	25	95225A350	00000
M24	25 mm	44 mm	2.8 mm to 3.5 mm	DIN 125	Black	10	95225A355	0000
M30	31 mm	56 mm	2.8 mm to 3.6 mm	DIN 125	Black	10	95225A360	00000

Insulating Sleeve Washers

Cover screw threads to stop electrical current in its tracks and prevent short circuits. These washers create a barrier between the screw threads and the mating surface when mounted in through holes. This barrier also extends the life of your assembly by preventing galvanic corrosion, which is when two different metals rust more quickly due to contact with each other.

Flat Edge

The flat edge distributes weight evenly to take pressure off screw heads.

Hard Fiber—The least likely to scratch or mar delicate mounting surfaces, such as printed circuit boards. These washers provide a moderate amount of electrical insulation, but they don't block current as well as plastic or ceramic washers.

		Sleeve						Temp. Range
	For Screw Size	Ht.	OD	ID	OD	Thk.	Overall Ht.	Min.	Max., ° F	Color	Pkg. Qty.		Pkg.
Hard Fiber



		No. 2	0.025"	0.154"	0.090"	0.250"	0.030"	0.055"	Not Rated	230	Black	50	93920A110	000000


		No. 4	0.025"	0.186"	0.116"	0.250"	0.030"	0.055"	Not Rated	230	Black	50	93920A120	00000
		No. 6	0.030"	0.186"	0.142"	0.313"	0.040"	0.070"	Not Rated	230	Black	50	93920A130	0000
		No. 8	0.030"	0.246"	0.168"	0.375"	0.040"	0.070"	Not Rated	230	Black	50	93920A140	00000
		No. 10	0.030"	0.312"	0.194"	0.375"	0.040"	0.070"	Not Rated	230	Black	50	93920A150	00000
		1/4"	0.030"	0.312"	0.254"	0.500"	0.040"	0.070"	Not Rated	230	Black	50	93920A160	00000
		3/8"	0.040"	0.437"	0.380"	0.625"	0.060"	0.100"	Not Rated	230	Black	50	93920A170	00000

Easy-Machine Hard Fiber Sheets

Also known as vulcanized fiber, these hard fiber sheets can be readily machined and punched into custom parts. They're constructed from lightweight cotton fabric that's been chemically treated to make them hard and dense. Use hard fiber to make gears and bushings.

										12" Wide × 12" Long		24" Wide × 39" Long		39" Wide × 48" Long
Thk.	Thk. Tolerance	Tensile Strength, psi	Hardness	Mil. Spec.	Flammability Rating	Color	Max. Temp., ° F	Impact Strength, ft·lbf/in	For Use Outdoors		Each		Each		Each
0.02"	-0.002" to 0.002"	9,000 to 21,000	Rockwell R70 (Hard)	MIL-I-695	UL 94 HB	Gray	235	1.8 to 2.5	No	8490K13	000000	8490K23	000000	8490K33	000000
0.03"	-0.003" to 0.003"	9,000 to 21,000	Rockwell R70 (Hard)	MIL-I-695	UL 94 HB	Gray	235	1.8 to 2.5	No	8490K14	00000	8490K24	00000	8490K34	00000
1/16"	-0.005" to 0.005"	9,000 to 21,000	Rockwell R80 (Hard)	MIL-F-10336, MIL-F-1148	UL 94 HB	Gray	235	1.8 to 2.5	No	8652K73	00000	8652K83	00000	8652K93	000000
3/32"	-0.007" to 0.007"	9,000 to 21,000	Rockwell R80 (Hard)	MIL-F-10336, MIL-F-1148	UL 94 HB	Gray	235	1.8 to 2.5	No	8652K74	00000	8652K84	000000	8652K94	000000
1/8"	-0.015" to 0.015"	9,000 to 21,000	Rockwell R80 (Hard)	MIL-F-10336, MIL-F-1148	UL 94 HB	Gray	235	1.8 to 2.5	No	8652K75	00000	8652K85	000000	8652K95	000000
3/16"	-0.015" to 0.015"	9,000 to 21,000	Rockwell R80 (Hard)	MIL-F-10336, MIL-F-1148	UL 94 HB	Gray	235	1.8 to 2.5	No	8652K76	00000	8652K86	000000	8652K96	000000
1/4"	-0.015" to 0.015"	9,000 to 21,000	Rockwell R80 (Hard)	MIL-F-10336, MIL-F-1148	UL 94 HB	Gray	235	1.8 to 2.5	No	8652K77	00000	8652K87	000000	8652K97	000000
3/8"	-0.02" to 0.02"	9,000 to 21,000	Rockwell R80 (Hard)	MIL-F-10336, MIL-F-1148	UL 94 HB	Gray	235	1.8 to 2.5	No	8652K78	000000	8652K88	000000	8652K98	00000000
1/2"	-0.025" to 0.025"	9,000 to 21,000	Rockwell R80 (Hard)	MIL-F-10336, MIL-F-1148	UL 94 HB	Gray	235	1.8 to 2.5	No	8652K79	000000	8652K89	000000	8652K99	00000000

Electrically Insulating Hard Fiber

Widely known as fishpaper and vulcanized fiber, these thin sheets offer better electrical insulation than standard hard fiber sheets. They are constructed from lightweight cotton fabric that's been chemically treated to make it hard and dense.

										6" Wide × 12" Long		12" Wide × 12" Long		24" Wide × 39" Long		39" Wide × 48" Long		39" Wide × 60" Long
Thk.	Thk. Tolerance	Tensile Strength, psi	Hardness	Mil. Spec.	Flammability Rating	Color	Max. Temp., ° F	Impact Strength, ft·lbf/in	For Use Outdoors		Each		Each		Each		Each		Each
0.005"	-0.001" to 0.001"	Not Rated	Rockwell R70 (Hard)	MIL-I-695	UL 94 HB	Gray	235	2.5	No	8490K101	00000	8490K15	00000	8490K25	000000	8490K35	000000	———	0
0.01"	-0.001" to 0.001"	Not Rated	Rockwell R70 (Hard)	MIL-I-695	UL 94 HB	Gray	235	2.5	No	8490K102	0000	8490K11	0000	8490K21	00000	8490K31	00000	8490K103	000000
0.015"	-0.002" to 0.002"	Not Rated	Rockwell R70 (Hard)	MIL-I-695	UL 94 HB	Gray	235	2.5	No	8490K104	0000	8490K12	0000	8490K22	00000	8490K32	00000	8490K105	00000
0.02"	-0.002" to 0.002"	Not Rated	Rockwell R70 (Hard)	MIL-I-695	UL 94 HB	Gray	235	2.5	No	8490K106	0000	8490K37	00000	8490K38	00000	8490K39	00000	———	0
0.025"	-0.003" to 0.003"	Not Rated	Rockwell R70 (Hard)	MIL-I-695	UL 94 HB	Gray	235	2.5	No	8490K107	00000	8490K16	00000	8490K26	00000	8490K36	000000	———	0
0.03"	-0.003" to 0.003"	Not Rated	Rockwell R70 (Hard)	MIL-I-695	UL 94 HB	Gray	235	2.5	No	8490K108	00000	8490K51	00000	8490K52	00000	8490K53	00000	———	0
0.04"	-0.004" to 0.004"	Not Rated	Rockwell R70 (Hard)	MIL-I-695	UL 94 HB	Gray	235	2.5	No	8490K109	00000	8490K54	00000	8490K55	000000	———	0	———	0
0.045"	-0.005" to 0.005"	Not Rated	Rockwell R70 (Hard)	MIL-I-695	UL 94 HB	Gray	235	2.5	No	8490K111	00000	8490K57	00000	8490K58	000000	———	0	———	0
0.062"	-0.007" to 0.007"	10,000 to 21,000	Rockwell R70 (Hard)	MIL-I-695	UL 94 HB	Gray	235	2.5	No	———	0	8490K61	00000	8490K62	000000	8490K63	000000	———	0

Sealing Washers

Prevent leaks while distributing weight evenly under nuts and screws. These washers compress as you tighten to keep air and fluid in, and dust and contaminants out. Use them anywhere you need a tight seal, such as protecting electronics from moisture or keeping lubricants contained in machinery.

Hard Fiber

An economical alternative to metal crush washers, these compress easily to create a seal with less effort. However, fiber washers degrade faster than metal washers and aren't as heat resistant. They also don't seal quite as tightly as their plastic or rubber counterparts. These washers are reusable, as long as the material isn't damaged.

	ID, mm	OD, mm	Thk., mm	Specs. Met	Pkg. Qty.		Pkg.
Hard Fiber



	M5	5	8	0.8	DIN 7603	100	90449A110	00000


	M5	5	10	0.8	DIN 7603	100	90449A120	0000
	M6	6	9	0.8	DIN 7603	100	90449A130	0000
	M6	6	10	0.8	DIN 7603	100	90449A140	0000
	M8	8	12	0.8	DIN 7603	100	90449A150	0000
	M8	8	14	0.8	DIN 7603	100	90449A160	0000
	M10	10	14	0.8	DIN 7603	100	90449A170	0000
	M10	10	16	1	DIN 7603	100	90449A180	0000
	M12	12	16	0.8	DIN 7603	100	90449A190	0000
	M12	12	18	1	DIN 7603	100	90449A210	0000
	M12	12	20	0.8	DIN 7603	100	90449A220	0000


	M12	12	24	0.8	DIN 7603	100	90449A230	0000
	M14	14	18	1	DIN 7603	100	90449A240	0000
	M14	14	24	0.8	DIN 7603	100	90449A250	0000
	M16	16	21	0.8	DIN 7603	100	90449A260	0000
	M18	18	22	0.8	DIN 7603	100	90449A270	0000
	M18	18	24	0.8	DIN 7603	100	90449A280	0000
	M22	22	27	0.8	DIN 7603	100	90449A290	0000