Stat-O-Seal Washers | McMaster-Carr

Filter by

System of Measurement

Screw Size

Material

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 Pressure

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

Maximum Temperature

REACH

Seal Hardness

Minimum Temperature

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	000000000	000000


		No. 6	0.13"	0.385"	0.036" to 0.044"	10,800	200	-40	225	Black	10	000000000	00000
		No. 8	0.156"	0.385"	0.036" to 0.044"	8,000	200	-40	225	Black	1	000000000	0000
		No. 10	0.18"	0.443"	0.045" to 0.055"	6,200	200	-40	225	Black	1	000000000	0000
		1/4"	0.24"	0.505"	0.045" to 0.055"	5,000	200	-40	225	Black	10	000000000	00000
		5/16"	0.301"	0.603"	0.045" to 0.055"	3,600	200	-40	225	Black	10	000000000	00000
		3/8"	0.364"	0.666"	0.045" to 0.055"	3,400	200	-40	225	Black	10	000000000	00000
		7/16"	0.427"	0.76"	0.045" to 0.055"	3,600	200	-40	225	Black	5	000000000	00000
		1/2"	0.49"	0.88"	0.045" to 0.055"	4,200	200	-40	225	Black	10	000000000	00000
		9/16"	0.552"	1.067"	0.045" to 0.055"	6,600	200	-30	225	Black	5	000000000	00000
		5/8"	0.615"	1.193"	0.045" to 0.055"	7,500	200	-40	225	Black	5	000000000	00000


		3/4"	0.74"	1.322"	0.059" to 0.069"	5,700	200	-40	225	Black	5	000000000	00000
		7/8"	0.864"	1.51"	0.059" to 0.069"	6,000	200	-30	225	Black	1	000000000	0000
		1"	0.988"	1.76"	0.059" to 0.069"	7,000	200	-40	225	Black	1	000000000	0000
		1 1/8"	1.106"	1.885"	0.059" to 0.069"	4,900	200	-10	240	Black	1	000000000	0000
		1 1/4"	1.229"	2.01"	0.059" to 0.069"	4,600	200	-10	240	Black	1	000000000	0000
		M2	1.8 mm	4.5 mm	0.9 mm to 1.1 mm	7,300	200	-10	240	Black	10	000000000	00000
		M2.5	2.2 mm	5.0 mm	0.9 mm to 1.1 mm	6,600	200	-10	240	Black	10	000000000	00000
		M3	2.7 mm	6.0 mm	0.9 mm to 1.1 mm	6,400	200	-10	240	Black	10	000000000	00000
		M4	3.7 mm	7.0 mm	0.9 mm to 1.1 mm	5,500	200	-10	240	Black	10	000000000	00000
		M5	4.8 mm	9.8 mm	0.9 mm to 1.2 mm	15,200	200	-30	220	Black	5	000000000	00000


		M6	5.8 mm	11.3 mm	1.1 mm to 1.4 mm	12,800	200	-30	220	Black	5	000000000	00000
		M8	7.8 mm	13.5 mm	1.1 mm to 1.4 mm	7,900	200	-30	220	Black	5	000000000	00000
		M10	9.7 mm	15.3 mm	1.1 mm to 1.4 mm	7,200	200	-30	220	Black	5	000000000	00000
		M12	11.7 mm	19.3 mm	1.1 mm to 1.4 mm	7,100	200	-30	220	Black	5	000000000	00000
		M14	13.7 mm	22.4 mm	1.1 mm to 1.4 mm	8,000	200	-30	220	Black	5	000000000	00000
		M16	15.7 mm	27.1 mm	1.1 mm to 1.4 mm	12,500	200	-30	220	Black	5	000000000	00000
		M20	19.6 mm	33.3 mm	1.5 mm to 1.8 mm	4,900	200	-10	240	Black	5	000000000	00000
		M22	21.6 mm	31.4 mm	1.1 mm to 1.4 mm	3,700	200	-10	240	Black	5	000000000	00000
		M24	23.7 mm	43.9 mm	1.5 mm to 1.8 mm	5,500	200	-10	240	Black	1	000000000	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	000000000	00000


				M6	5.8 mm	11.3 mm	1.1 mm to 1.4 mm	3,600	200	0	390	Black	10	000000000	00000
				M8	7.8 mm	13.5 mm	1.1 mm to 1.4 mm	3,100	200	0	390	Black	5	000000000	00000
				M10	9.7 mm	15.3 mm	1.1 mm to 1.4 mm	2,700	200	0	390	Black	5	000000000	00000
				M12	11.7 mm	19.3 mm	1.1 mm to 1.4 mm	2,900	200	0	390	Black	5	000000000	00000
				M14	13.6 mm	22.3 mm	1.1 mm to 1.4 mm	2,900	200	0	390	Black	1	000000000	0000
				M16	15.6 mm	27.1 mm	1.1 mm to 1.4 mm	3,100	200	0	390	Black	1	000000000	0000
				M20	19.6 mm	33.3 mm	1.5 mm to 1.8 mm	3,000	200	0	390	Black	1	000000000	00000