0.042" ID O-Rings | McMaster-Carr

Made of Buna-N, these O-rings resist grease, hydraulic oil, and motor oil—plus mild chemicals and water. However, Buna-N is not for use with brake fluid. These O-rings are commonly used to create multidirectional seals between two parts in power transmission assemblies, hydraulic cylinders, and pneumatic cylinders. They resist compression and tearing to keep their shape over time. All have shelf life, a cure date, and a traceable lot number printed on the package.

Inch

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-49	50-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	-30 to 215	Black	100	9452K112	00000	00000	00000

Oil-Resistant Buna-N O-Ring Assortments

1,110 Pieces

With a range of sizes on hand, you’ll always have the right O-ring for the job. Made of Buna-N, the O-rings in these assortments resist grease, hydraulic oil, and motor oil. They also withstand mild chemicals and water, although they’ll break down from exposure to brake fluid. Their resistance to compression and tearing helps them keep their shape over time, so they’re often used to seal power transmission assemblies and pneumatic cylinders.

1,110 Pieces—Assortments with 1,110 pieces include a mix of standard O-rings and O-rings for straight-thread connections, also known as Boss O-rings.

	Specs. Met	Temp. Range, ° F		Each
Durometer 70A (Medium)







	Black

	1,110	150	Dash Numbers 001-046, 110-151, 210-237, 325-338, 901-914, 916, 918, 920, 924, 928, 932	ASTM D2000, SAE AS568, SAE J200	-25 to 250	9000K14	0000000

Chemical-Resistant Viton® Fluoroelastomer O-Ring Assortments

1,110 Pieces

Keep a selection of O-rings on hand so you always have the size you need. Made of Viton® fluoroelastomer, the O-rings in these assortments combine the oil resistance of Buna-N with the heat tolerance of silicone. They also resist a variety of chemicals, including benzene, butyl alcohol, and ethylene glycol. They’re often used to seal equipment in crude oil refineries.

1,110 Pieces—Assortments with 1,110 pieces include a mix of standard O-rings and O-rings for straight-thread connections, also known as Boss O-rings.

	Specs. Met	Temp. Range, ° F		Each
Durometer 75A (Medium)







	Black

	1,110	150	Dash Numbers 001-046, 110-151, 210-237, 325-338, 901-914, 916, 918, 920, 924, 928, 932	ASTM D2000, SAE AS568, SAE J200	-15 to 400	9465K11	0000000

Square-Profile Chemical-Resistant Viton® Fluoroelastomer O-Rings

With flat edges on all four sides, these Viton® fluoroelastomer square-profile O-rings cover more surface than round-profile O-rings for a better seal in static applications, such as hose, pipe, and faucet connections. They resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. All have shelf life, a cure date, and a traceable lot number printed on the bag.

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 75A (Medium)	ASTM D2000, SAE AS568	-10 to 400	Black	25	1170N12	000000	00000

Oil-Resistant Soft Buna-N O-Rings

For a better seal in low-pressure applications, such as hydraulic return lines and oil drain plugs, these O-rings are softer than standard Buna-N O-rings. They offer the same level of oil resistance and are often used with hydraulic oil and motor oil.

Inch

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 50A (Soft)	ASTM D2000, SAE AS568, SAE J200	-30 to 225	Black	100	2418T312	000000	000000

High-Temperature Soft Silicone O-Rings

Easier to compress than standard silicone O-rings, these O-rings create a better seal in enclosures, reservoirs, and other low-pressure equipment. They can withstand temperatures up to 400° F. All have shelf life, a cure date, and a traceable lot number printed on the bag.

Inch

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 50A (Soft)	ASTM D2000, SAE AS568	-85 to 400	Red	25	1173N002	00000	00000

FDA-Compliant Chemical-Resistant Soft Viton® Fluoroelastomer O-Rings

Made of Viton® fluoroelastomer, these O-rings won’t degrade when exposed to chemicals such as sulfuric acid, butyl alcohol, and ethylene glycol. They’re also FDA compliant for direct contact with food. Since they’re softer and easier to compress than standard Viton® O-rings, they form a better seal in low-pressure applications. They offer the same oil resistance as Buna-N O-rings and withstand high temperatures, making them ideal for food lines with hot oil. All have shelf life, a cure date, and a traceable lot number printed on the bag.

		Fractional											Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Food Industry Std.	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 60A (Soft)	SAE AS568	FDA Compliant 21 CFR 177.2600	-15 to 400	White	25	1284N102	00000	00000

High-Temperature Parker S1138 Silicone O-Rings

Use these O-rings in temperatures up to 400° F. Made of Parker S1138 silicone, they’re pure enough for food or pharmaceutical applications—they’re USP VI certified. These O-rings are also FDA compliant for direct contact with food. All come with a cure date and a traceable lot number printed on the bag.

		Fractional												Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Food Industry Std.	USP Class	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-49	50-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	FDA Compliant 21 CFR 177.2600	VI	-60 to 400	Red	25	9396K102	00000	00000	00000

Oil-Resistant Hard Buna-N O-Rings

Harder than standard Buna-N O-rings, these 90A durometer O-rings are more durable and wear resistant. They resist petroleum and grease, so they’re often used in hydraulic and pneumatic systems. All have shelf life, cure date, and a traceable lot number printed on the bag.

Inch

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional Width (0.050" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 90A (Hard)	ASTM D2000, SAE AS568, SAE J200	-30 to 250	Black	100	5308T111	00000	00000

Water- and Steam-Resistant Parker E0603 EPDM O-Rings

Trusted for their quality and consistency, these E0603 EPDM O-rings resist water, steam, and glycol-based fluids, including brake fluid. They’re often used to seal plumbing and refrigeration systems, since they won’t swell or break down in moist environments. All have a cure date and traceable lot number printed on the bag.

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-49	50-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	-70 to 250	Black	25	9557K112	00000	00000	00000

Low-Temperature Chemical-Resistant Mil. Spec. Fluorosilicone O-Rings

Create seals in temperatures as low as -65° F. Made of fluorosilicone, these O-rings have the same chemical resistance as Viton® fluoroelastomer O-rings, but they’re more flexible in the cold. They resist ethanol, ethylene glycol, and isopropyl alcohol. All meet MIL-R-25988 standards for performance and quality. All have shelf life, a cure date, and a traceable lot number printer on the bag.

		Fractional											Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Mil. Spec.	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	MIL-R-25988	-65 to 390	Blue	5	8333T112	00000	00000

Oil-Resistant Mil. Spec. Buna-N O-Rings

Choose these O-rings for their adherence to strict military standards for material and construction. Made of Buna-N, they stand up to a variety of oils and fuels as well as ammonia, ethylene glycol, and isopropyl alcohol. They’re also resilient and tear resistant. These O-rings are made in the U.S.

MIL-I-45208—O-rings that meet MIL-I-45208 have undergone rigorous inspection for quality control.

MIL-P-5315—O-rings that meet MIL-P-5315 are the best choice for use with hydrocarbon fuels. They’re often used in engine fuel systems in airplanes and other vehicles.

MIL-P-25732—O-rings that meet MIL-P-25732 are the most common choice for use with hydraulic oil. They’ll withstand short periods of use at high temperatures.

		Fractional											Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Mil. Spec.	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 65A (Medium)	ASTM D2000, SAE AS568, SAE AS3578, SAE J200	MIL-I-45208	-20 to 250	Black	25	5018T112	000000	000000


		002	3/64	9/64	0.042"	0.142"	Durometer 65A (Medium)	ASTM D2000, SAE AS568, SAE J200	MIL-P-5315	-65 to 155	Black	50	4464T112	00000	00000
		002	3/64	9/64	0.042"	0.142"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	MIL-P-25732	-30 to 250	Black	50	4198T112	00000	00000

Low-Outgassing Chemical-Resistant Soft Viton® Fluoroelastomer O-Rings

Tested to meet ASTM E595, a standard used by NASA, these O-rings give off almost no volatile emissions that could damage sensitive electronics, even in a vacuum. They’re softer than standard Viton®, so they better conform to irregular surfaces. And thanks to their material, they resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. Their round profile is good for sealing both moving and stationary parts. All are sized to the SAE standard AS568.

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 50A (Soft)	ASTM E595, SAE AS568	-15 to 400	Brown	10	9322N102	000000	000000

Chemical-Resistant Hard Viton® Fluoroelastomer O-Rings

With a 90A durometer, these O-rings are harder and more wear-resistant than standard Viton® fluoroelastomer O-rings. They hold up to the high pressures in fuel injectors and heavy duty hydraulic cylinders. They resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. All have shelf life, a cure date, and a traceable lot number printed on the bag.

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 90A (Hard)	ASTM D2000, SAE AS568, SAE J200	0 to 400	Black	50	8297T112	00000	00000

Oil- and Abrasion-Resistant Polyurethane O-Rings

More abrasion resistant than Buna-N O-rings, these polyurethane O-rings resist mineral oil, motor oil, and ethylene glycol. They have a round profile and are suitable for a wide range of static and dynamic sealing applications. All are sized to the SAE standard AS568.

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	-40 to 200	Black	1	9558K166	00000	00000

Chemical-Resistant Viton® Fluoroelastomer O-Rings

Made of Viton® fluoroelastomer, these O-rings combine the oil resistance of Buna-N with the heat tolerance of silicone. They also resist a variety of chemicals, including benzene, butyl alcohol, and ethylene glycol. They’re often used to seal hydraulic systems and equipment in crude oil refineries. All have shelf life, a cure date, and a traceable lot number printed on the bag.

Inch

Brown—Brown O-rings help you tell Viton® fluoroelastomer apart from other materials.

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Choose a Color	Pkg. Qty.		1-9	10-49	50-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 75A (Medium)	ASTM D2000, SAE AS568, SAE J200	0 to 400	Black, Brown	100	9464K266	00000	00000	00000

Ultra-Chemical-Resistant DuPont Kalrez 4079 O-Rings

Made of Kalrez 4079, these O-rings combine the chemical resistance of PTFE with the springy softness of Viton® fluoroelastomer. They hold up to a wide range of chemicals, such as acetone, methyl ethyl ketone (MEK), potassium hydroxide, and most acids.

Inch

		Fractional									Each
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 75A	ASTM D2000, SAE AS568, SAE J200	30 to 600	Black	9568K111	000000	000000

Water- and Weather-Resistant Neoprene O-Rings

Resistant to changing weather—from rainwater to sunlight—these neoprene O-rings are good for outdoor use. They’re often used in equipment exposed to the elements, including maritime systems, electrical enclosures, and HVAC units. Compared to EPDM O-rings, these neoprene O-rings have better resistance to oil and chemicals. However, they operate within a narrower temperature range. All have shelf life, cure date, and a traceable lot number printed on the bag.

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional Width (0.050" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	-40 to 225	Black	75	94115K002	00000	00000

High-Temperature Silicone O-Rings

Made of silicone, these O-rings can withstand temperatures up to 400° F or higher. They're FDA compliant for direct contact with food, so they're often used on hot food lines. They're also used to seal HVAC systems. All come with a cure date and a traceable lot number printed on the bag.

Inch

		Fractional											Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Food Industry Std.	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-49	50-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	FDA Compliant 21 CFR 177.2600	-65 to 400	Red	100	9186N113	00000	00000	00000

Chemical-Resistant Clean Room Viton® Fluoroelastomer O-Rings

Made and bagged in an ISO Class 7 clean room, these O-rings won’t shed particles. They’re made of Viton® fluoroelastomer, which resists chemicals such as benzene, butyl alcohol, and ethylene glycol. All have shelf life, a cure date, and a traceable lot number printed on the bag.

		Fractional													Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Clean Room Std.	Specs. Met	Food Industry Std.	USP Class	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 70A (Medium)	Fed. Std. Class 10,000; ISO Class 7	ASTM D2000, SAE AS568, SAE J200	FDA Compliant 21 CFR 177.2600	VI	-15 to 400	Black	25	1309N202	000000	000000

Weather- and Oil-Resistant HNBR O-Rings

A step up from Buna-N, these HNBR O-rings contain extra hydrogen to better resist chemicals, weather, and abrasion. They won’t swell from contact with grease and acid, making them a good choice in engine, hydraulic, and HVAC systems. Because they won’t deteriorate from ozone, UV, and oxidation, these O-rings are also good for outdoor use. However, they won’t withstand solvents or strong acids like Viton® fluoroelastomer O-rings do. They’re also known as hydrogenated nitrile and highly saturated nitrile O-rings.

All have shelf life, cure date, and a traceable lot number printed on the bag.

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional Width (0.050" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	-40 to 250	Green	100	8551N12	00000	00000

Ultra-Chemical-Resistant FFKM 4079 O-Rings

Get the same chemical and heat resistance as Kalrez 4079 without the brand name. Even at 600° F, these FFKM O-rings resist a wide range of chemicals, including acetone, methyl ethyl ketone (MEK), potassium hydroxide, and most acids. All have a cure date and a traceable lot number printed on the bag.

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 75A (Medium)	ASTM D2000, SAE AS568, SAE J200	15 to 600	Black	1	8666N12	000000	000000

Low-Outgassing Chemical-Resistant Viton® Fluoroelastomer O-Rings

Tested to meet ASTM E595, a standard used by NASA, these O-rings give off almost no volatile emissions that could damage sensitive electronics, even in a vacuum. They’re made of Viton® fluoroelastomer, so they also resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. A round profile is good for sealing both moving and stationary parts. All are sized to the SAE standard AS568.

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 75A (Medium)	ASTM E595, SAE AS568	-10 to 390	Black	10	9327N12	00000	00000

Chemical-Resistant Mil. Spec. Viton® Fluoroelastomer O-Rings

Made of Viton® fluoroelastomer, these O-rings meet MIL-R-83248 standards. They stay strong when used with chemicals such as benzene, butyl alcohol, and ethylene glycol. You’ll often find them used in aerospace fuel and hydraulic systems. All have shelf life, a cure date, and a traceable lot number printed on the bag.

		Fractional											Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Mil. Spec.	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 75A (Medium)	ASTM D2000, SAE AS568, SAE J200	MIL-R-83248	5 to 400	Black	50	1201T12	00000	00000

High-Purity Ultra-Chemical-Resistant DuPont Kalrez 6230 O-Rings

Create seals for use in semiconductor manufacturing, food processing, and other highly controlled applications. More pure than Kalrez 4079 O-rings, these Kalrez 6230 O-rings won’t leach contaminants into your line. They’re FDA compliant for direct contact with food, as well as 3-A and USP VI certified. These O-rings hold up to ammonia, glycerin, solvents, synthetic lubricants, and most acids.

		Fractional											Each
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Food Industry Std.	USP Class	Temp. Range, ° F	Color		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 75A (Medium)	SAE AS568	3-A Certified 18-03, FDA Compliant 21 CFR 177.2600	VI	30 to 500	Black	1285N12	000000	000000

Super-Resilient Chemical-Resistant Viton® Fluoroelastomer O-Rings

Made for demanding applications, these O-rings hold up to constant motion, repeated compression, and extreme temperatures. They’re often used for centrifugal pumps and high-pressure hydraulic valves in chemical processing systems. These O-rings have a higher tensile strength than standard Viton® fluoroelastomer O-rings and withstand a wider range of temperatures. They also hold their shape four times better when tested to ASTM D395 standards for compression set. You can use them with boric acid, butyl alcohol, ethylene glycol, and other chemicals. They have shelf life, a cure date, and a traceable lot number printed on the bag.

Inch

		Fractional											Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Tensile Strength, psi	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 75A (Medium)	2,030	ASTM D395, ASTM D2000, SAE AS568, SAE J200	-15 to 525	Black	25	1288N22	00000	00000

Steam- and Ultra-Chemical-Resistant Aflas O-Rings

Often used in drilling systems, these Aflas O-rings hold up to petroleum fluids. They also withstand steam and chemicals such as ammonia, calcium hydroxide, and boric acid. All have shelf life, a cure date, and a traceable lot number printed on the bag.

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 80A (Hard)	ASTM D2000, SAE AS568	25 to 450	Black	25	5240T249	00000	00000

Water- and Steam-Resistant EPDM O-Rings

Made of EPDM, these O-rings have excellent resistance to water, steam, and glycol-based fluids, including brake fluid. They’re often used to seal plumbing and refrigeration systems, since they won’t swell or break down in moist environments. All have shelf life, a cure date, and a traceable lot number printed on the bag.

Inch

		Fractional										Pkg.
	Dash No.	ID	OD	ID	OD	Hardness	Specs. Met	Temp. Range, ° F	Color	Pkg. Qty.		1-9	10-49	50-Up
3/64 Fractional (Width 0.05" Wide)



		002	3/64	9/64	0.042"	0.142"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	-65 to 300	Black	25	8785N498	00000	00000	00000