Stat-O-Seal Washers | McMaster-Carr

Filter by

Screw Size

Material

System of Measurement

Thickness

Performance

Environment

Maximum Pressure for Fluids

Less than 3,000 psi

3,000 psi to 3,999 psi

4,000 psi to 4,999 psi

5,000 psi to 9,999 psi

10,000 psi or greater

Hardness

Maximum Temperature

Seal Hardness

Minimum Temperature

REACH

RoHS

Export Control Classification Number (ECCN)

EAR99

DFARS Specialty Metals

Exempt

Forward

How can we improve?

38 Products

Performance

Weather Resistant

Withstand long-term exposure to sunlight, rain, and ozone

8 products

Chemical Resistant

Stands up to solvents, cleaners, and other harsh substances

8 products

Performance

Corrosion Resistant

Won't rust in wet and outdoor environments

8 products

High Temperature

Hold their seal, even at scorching temperatures

8 products

High-Pressure Bonded Sealing Washers

Tested to hold up to high pressures, these washers create the strongest seal of all to lock in air and fluid and keep equipment running efficiently. They are often used on flanged connections to prevent leaks in pumps, hydraulic systems, compressors, and other pressurized lines. The flexible rubber or plastic layer compresses to fills gaps, while the metal backing stops the washer from squeezing through the hole.

For Screw Heads

Fit under screw heads to stop leaks. These washers seal best on screws that aren't threaded all the way up to the head. Reuse them a handful of times, as long as the material isn't damaged.

Oil-Resistant Zinc-Plated Steel and Buna-N—These washers won't swell or soften when they touch oil, grease, and fuel. However, they will degrade if exposed to synthetic lubricants. They are also are more susceptible to rusting than 18-8 and 316 stainless steel.

Chemical-Resistant 18-8 Stainless Steel and Fluoroelastomer—These washers resist corrosion better than zinc-plated steel, so they're less likely to rust in wet and outdoor environments. The seal withstands high temperatures and won't degrade when exposed to acids, alcohols, solvents, synthetic lubricants, and harsh detergents.

					Max. Pressure, psi		Temp. Range, ° F
	For Screw Size	ID	OD	Thk.	For Fluids	For Gases	Min.	Max.	Color	Pkg. Qty.		Pkg.
Oil-Resistant Zinc-Plated Steel and Buna-N


		No. 4	0.102"	0.25"	0.035" to 0.045"	7,000	200	-10	240	Black	10	93783A005	000000
		No. 6	0.13"	0.385"	0.036" to 0.044"	10,800	200	-40	225	Black	10	93783A007	00000
		No. 8	0.156"	0.385"	0.036" to 0.044"	8,000	200	-40	225	Black	1	93783A009	0000
		No. 10	0.18"	0.443"	0.045" to 0.055"	6,200	200	-40	225	Black	1	93783A011	0000
		1/4"	0.24"	0.505"	0.045" to 0.055"	5,000	200	-40	225	Black	10	93783A029	00000
		5/16"	0.301"	0.603"	0.045" to 0.055"	3,600	200	-40	225	Black	10	93783A030	00000
		3/8"	0.364"	0.666"	0.045" to 0.055"	3,400	200	-40	225	Black	10	93783A031	00000
		7/16"	0.427"	0.76"	0.045" to 0.055"	3,600	200	-40	225	Black	5	93783A032	00000
		1/2"	0.49"	0.88"	0.045" to 0.055"	4,200	200	-40	225	Black	10	93783A033	00000
		9/16"	0.552"	1.067"	0.045" to 0.055"	6,600	200	-30	225	Black	5	93783A034	00000
		5/8"	0.615"	1.193"	0.045" to 0.055"	7,500	200	-40	225	Black	5	93783A035	00000
		3/4"	0.74"	1.322"	0.059" to 0.069"	5,700	200	-40	225	Black	5	93783A036	00000
		7/8"	0.864"	1.51"	0.059" to 0.069"	6,000	200	-30	225	Black	1	93783A046	0000
		1"	0.988"	1.76"	0.059" to 0.069"	7,000	200	-40	225	Black	1	93783A051	0000
		1 1/8"	1.106"	1.885"	0.059" to 0.069"	4,900	200	-10	240	Black	1	93783A056	0000
		1 1/4"	1.229"	2.01"	0.059" to 0.069"	4,600	200	-10	240	Black	1	93783A061	0000
		M2	1.8 mm	4.5 mm	0.9 mm to 1.1 mm	7,300	200	-10	240	Black	10	93786A501	00000
		M2.5	2.2 mm	5.0 mm	0.9 mm to 1.1 mm	6,600	200	-10	240	Black	10	93786A502	00000
		M3	2.7 mm	6.0 mm	0.9 mm to 1.1 mm	6,400	200	-10	240	Black	10	93786A503	00000
		M4	3.7 mm	7.0 mm	0.9 mm to 1.1 mm	5,500	200	-10	240	Black	10	93786A504	00000
		M5	4.8 mm	9.8 mm	0.9 mm to 1.2 mm	15,200	200	-30	220	Black	5	93786A100	00000
		M6	5.8 mm	11.3 mm	1.1 mm to 1.4 mm	12,800	200	-30	220	Black	5	93786A125	00000
		M8	7.8 mm	13.5 mm	1.1 mm to 1.4 mm	7,900	200	-30	220	Black	5	93786A150	00000
		M10	9.7 mm	15.3 mm	1.1 mm to 1.4 mm	7,200	200	-30	220	Black	5	93786A175	00000
		M12	11.7 mm	19.3 mm	1.1 mm to 1.4 mm	7,100	200	-30	220	Black	5	93786A200	00000
		M14	13.7 mm	22.4 mm	1.1 mm to 1.4 mm	8,000	200	-30	220	Black	5	93786A225	00000
		M16	15.7 mm	27.1 mm	1.1 mm to 1.4 mm	12,500	200	-30	220	Black	5	93786A250	00000
		M20	19.6 mm	33.3 mm	1.5 mm to 1.8 mm	4,900	200	-10	240	Black	5	93786A300	00000
		M22	21.6 mm	31.4 mm	1.1 mm to 1.4 mm	3,700	200	-10	240	Black	5	93786A325	00000
		M24	23.7 mm	43.9 mm	1.5 mm to 1.8 mm	5,500	200	-10	240	Black	1	93786A350	0000

		Chemical-Resistant 18-8 Stainless Steel and Fluoroelastomer


				M5	4.8 mm	9.8 mm	0.9 mm to 1.1 mm	3,700	200	0	390	Black	10	90467A205	00000
				M6	5.8 mm	11.3 mm	1.1 mm to 1.4 mm	3,600	200	0	390	Black	10	90467A206	00000
				M8	7.8 mm	13.5 mm	1.1 mm to 1.4 mm	3,100	200	0	390	Black	5	90467A208	00000
				M10	9.7 mm	15.3 mm	1.1 mm to 1.4 mm	2,700	200	0	390	Black	5	90467A210	00000
				M12	11.7 mm	19.3 mm	1.1 mm to 1.4 mm	2,900	200	0	390	Black	5	90467A212	00000
				M14	13.6 mm	22.3 mm	1.1 mm to 1.4 mm	2,900	200	0	390	Black	1	90467A214	0000
				M16	15.6 mm	27.1 mm	1.1 mm to 1.4 mm	3,100	200	0	390	Black	1	90467A216	0000
				M20	19.6 mm	33.3 mm	1.5 mm to 1.8 mm	3,000	200	0	390	Black	1	90467A220	00000