Dash Number 313 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		Actual								Pkg.
Dash Number	ID	OD	ID	OD	Hardness	Specifications Met	Temperature Range, °F	Color	Pkg. Qty.		1-9	10-49	50-Up
Wd.: 3/16 Fractional (0.21" Actual)
313	11/16	1 1/16	0.662"	1.082"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	-30° to 212°	Black	50	9452K386	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		Actual								Pkg.
Dash Number	ID	OD	ID	OD	Hardness	Specifications Met	Temperature Range, °F	Color	Pkg. Qty.		1-9	10-Up
Wd.: 3/16 Fractional (0.21" Actual)
313	11/16	1 1/16	0.662"	1.082"	Durometer 90A (Hard)	ASTM D2000, SAE AS568, SAE J200	-30° to 250°	Black	50	5308T344	00000	00000

X-Profile Oil-Resistant Buna-N O-Rings

With four points of contact for a strong seal, these X-profile O-rings are often used in dynamic applications, such as on pistons and rotating shafts. Also known as Quattro seals and X-rings, they resist rolling and twisting better than round- and square-profile O-rings. They also require less compression to seal, which reduces friction and extends their service life. These O-rings are made of Buna-N, which is resilient and tear resistant. They resist hydraulic and motor oil.

	Fractional		Actual								Pkg.
Dash Number	ID	OD	ID	OD	Hardness	Specifications Met	Temperature Range, °F	Color	Pkg. Qty.		1-9	10-Up
Wd.: 3/16 Fractional (0.21" Actual)
313	11/16	1 1/16	0.662"	1.082"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	-30° to 225°	Black	10	90025K622	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.

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

	Fractional		Actual								Pkg.
Dash Number	ID	OD	ID	OD	Hardness	Specifications Met	Temp. Range, °F	Color	Pkg. Qty.		1-9	10-Up
Wd.: 3/16 Fractional (0.21" Actual)
313	11/16	1 1/16	0.662"	1.082"	Durometer 65A (Medium)	ASTM D2000, MIL-I-45208, SAE AS3578, SAE AS568, SAE J200	-20° to 250°	Black	25	5018T336	000000	000000

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		Actual								Pkg.
Dash Number	ID	OD	ID	OD	Hardness	Specifications Met	Temperature Range, °F	Color	Pkg. Qty.		1-9	10-Up
Wd.: 3/16 Fractional (0.21"Actual)
313	11/16	1 1/16	0.662"	1.082"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	-40° to 200°	Black	1	9558K331	00000	00000

Chemical-Resistant Viton® Fluoroelastomer O-Rings

These Viton® fluoroelastomer O-rings resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. They have a round profile and are suitable for both static and dynamic sealing applications.

Inch O-rings have a dash number and are sized to the SAE standard AS568.

Inch

	Fractional		Actual
Dash Number	ID	OD	ID	OD	Hardness	Specifications Met	Temperature Range, °F	Color	Pkg. Qty.		Pkg.
Wd.: 3/16 Fractional (0.21" Actual)
313	11/16	1 1/16	0.662"	1.082"	Durometer 75A (Medium)	ASTM D2000, SAE AS568, SAE J200	0° to 400°	Black	15	9464K586	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		Actual								Pkg.
Dash Number	ID	OD	ID	OD	Hardness	Specifications Met	Temperature Range, °F	Color	Pkg. Qty.		1-9	10-49	50-Up
Wd.: 3/16 Fractional (0.21" Actual)
313	11/16	1 1/16	0.662"	1.082"	Durometer 70A (Medium)	ASTM D2000, FDA Compliant 21 CFR 177.2600, SAE AS568, SAE J200, USP VI Certified	-60° to 400°	Red	25	9396K284	000000	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		Actual								Pkg.
Dash Number	ID	OD	ID	OD	Hardness	Specifications Met	Temperature Range, °F	Color	Pkg. Qty.		1-9	10-Up
Wd.: 3/16 Fractional (0.21" Actual)
313	11/16	1 1/16	0.662"	1.082"	Durometer 50A (Soft)	ASTM D2000, SAE AS568	-85° to 400°	Red	5	1173N532	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		Actual								Pkg.
Dash Number	ID	OD	ID	OD	Hardness	Specifications Met	Temperature Range, °F	Color	Pkg. Qty.		1-9	10-49	50-Up
Wd.: 3/16 Fractional (0.21" Actual)
313	11/16	1 1/16	0.662"	1.082"	Durometer 70A (Medium)	ASTM D2000, FDA Compliant 21 CFR 177.2600, SAE AS568, SAE J200	-65° to 400°	Red	25	9186N332	00000	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		Actual								Pkg.
Dash Number	ID	OD	ID	OD	Hardness	Specifications Met	Temperature Range, °F	Color	Pkg. Qty.		1-9	10-49	50-Up
Wd.: 3/16 Fractional (0.21" Actual)
313	11/16	1 1/16	0.662"	1.082"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	-70° to 250°	Black	70	9557K289	000000	000000	000000

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		Actual								Pkg.
Dash Number	ID	OD	ID	OD	Hardness	Specifications Met	Temperature Range, °F	Color	Pkg. Qty.		1-9	10-49	50-Up
Wd.: 3/16 Fractional (0.21" Actual)
313	11/16	1 1/16	0.662"	1.082"	Durometer 70A (Medium)	ASTM D2000, SAE AS568, SAE J200	-65° to 300°	Black	70	8785N215	000000	00000	00000