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Oil-Resistant Buna-N O-Rings

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.

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) | |||||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 70A (Medium) | ASTM D2000, SAE AS568, SAE J200 | -30° to 212° | Black | 50 | 9452K205 | 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.

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) | ||||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 90A (Hard) | ASTM D2000, SAE AS568, SAE J200 | -30° to 250° | Black | 50 | 5308T341 | 00000 | 00000 |
Square-Profile Oil-Resistant Buna-N O-Rings

With flat edges on all four sides, these O-rings make contact with a larger surface area than round-profile O-rings. The increased contact creates a better seal in static applications, such as hose, pipe, and faucet connections. However, these O-rings aren’t as good of a choice in dynamic applications, where the flat edges cause higher friction that leads to increased wear. Made from Buna-N, they resist tearing and stand up to hydraulic and motor oils.

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 (0.203" Actual) | ||||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.881" | Durometer 70A (Medium) | ASTM D2000, SAE AS568, SAE J200 | -30° to 212° | Black | 25 | 4061T411 | 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) | ||||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 65A (Medium) | ASTM D2000, MIL-I-45208, SAE AS3578, SAE AS568, SAE J200 | -20° to 250° | Black | 25 | 5018T333 | 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) | ||||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 70A (Medium) | ASTM D2000, SAE AS568, SAE J200 | -40° to 200° | Black | 1 | 9558K164 | 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.

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) | |||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 75A (Medium) | ASTM D2000, SAE AS568, SAE J200 | 0° to 400° | Black | 10 | 9464K584 | 00000 |
Chemical-Resistant Brown Viton® Fluoroelastomer O-Rings
Because one black O-ring looks just like another, these Viton® fluoroelastomer O-rings are brown for easy identification. They resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. All have a round profile and are suitable for both static and dynamic sealing applications. O-rings have shelf life, cure date, and traceable lot number printed on the bag.
Inch O-rings have a dash number and are sized to the SAE standard AS568.
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) | |||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 75A (Medium) | ASTM D2000, SAE AS568, SAE J200 | 0° to 400° | Brown | 10 | 5267T258 | 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) | |||||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 70A (Medium) | ASTM D2000, FDA Compliant 21 CFR 177.2600, SAE AS568, SAE J200, USP VI Certified | -60° to 400° | Red | 25 | 9396K281 | 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.

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) | ||||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 50A (Soft) | ASTM D2000, SAE AS568 | -85° to 400° | Red | 5 | 1173N528 | 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.

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) | |||||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 70A (Medium) | ASTM D2000, FDA Compliant 21 CFR 177.2600, SAE AS568, SAE J200 | -65° to 400° | Red | 25 | 9186N329 | 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) | |||||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 70A (Medium) | ASTM D2000, SAE AS568, SAE J200 | -70° to 250° | Black | 75 | 9557K286 | 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.

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) | |||||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 70A (Medium) | ASTM D2000, SAE AS568, SAE J200 | -65° to 300° | Black | 75 | 8785N212 | 000000 | 00000 | 00000 |
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 | 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) | ||||||||||||
| 310 | 1/2 | 7/8 | 0.475" | 0.895" | Durometer 70A (Medium) | ASTM D2000, SAE AS568, SAE J200 | -40° to 225° | Black | 75 | 94115K31 | 000000 | 000000 |

























