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    18 Products
    About O-Rings
    industrial info icon

    Find the right size, compare compatible materials, and choose the best cross section shape for your O-ring.

    Oil-Resistant Hard Buna-N O-Ring Assortments for Straight-Thread Connections

    Image of Product. Front orientation. O-Rings. Oil-Resistant Hard Buna-N O-Ring Assortments for Straight-Thread Connections.
    Keep a range of sizes on hand so that you always have the O-ring you need. Also known as boss O-rings, the O-rings in these assortments are sized to fit straight threaded fittings to prevent leaks. With a 90A durometer hardness, they're more wear resistant than standard Buna-N O-rings. They withstand motor oil, hydraulic fluid, and mild chemicals, so they're often installed in hydraulic and pneumatic systems.
    No. of
    Pieces
    No. of Sizes
    Included
    Includes
    Specs. Met
    Temp. Range,
    ° F
    Hardness
    Color
    Each
    21220Dash Numbers 901-914, 916, 918, 920, 924, 928, 932ASTM D2000, SAE AS568-25 to 250Durometer 90A (Hard)Black9749K29000000

    Oil-Resistant Hard Buna-N O-Rings for Straight-Thread Connections

    Also known as boss O-rings, these O-rings are sized to fit straight threaded fittings to prevent leaks. With a 90A durometer hardness, they’re more wear resistant than standard Buna-N O-rings. They withstand motor oil, hydraulic fluid, and mild chemicals, so they’re often installed in hydraulic and pneumatic systems.
    Inch
    Image of Product. Front orientation. O-Rings. Oil-Resistant Hard Buna-N O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Oil-Resistant Hard Buna-N O-Rings for Straight-Thread Connections.
    Pkg.
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    904
    1/4"0.072"0.351"0.495"Durometer 90A (Hard)ASTM D2000, SAE AS568, SAE J200-40 to 240Black1009751K1140000000000

    Oil-Resistant Hard Buna-N O-Ring Assortments

    Image of Product. Front orientation. O-Rings. Oil-Resistant Hard Buna-N O-Ring Assortments, 240 Pieces.

    240 Pieces

    Stock a variety of sizes so you always have the O-ring you need. With a 90A durometer, the O-rings in these assortments are harder and more wear-resistant than standard Buna-N O-rings. They resist petroleum and grease, so they’re often used in hydraulic and pneumatic systems.
    240 Pieces—Assortments with 240 pieces come with O-rings sized for hydraulic applications, including straight-thread connections, face seal fittings, and Code 61 or 62 SAE flanges.
    No. of
    Pieces
    No. of Sizes
    Included
    Includes
    Specs. Met
    Temp. Range,
    ° F
    Hardness
    Color
    Each
    24024Dash Numbers 011, 012, 014, 016, 018, 021, 025, 210, 212, 214, 219, 222, 225, 228, 901-906, 908, 910, 912, 916ASTM D2000, SAE AS568, SAE J200-20 to 212Durometer 90A (Hard)Black9690K41000000

    Chemical-Resistant Hard Viton® Fluoroelastomer O-Ring Assortments for Straight-Thread Connection

    Image of Product. Front orientation. O-Rings. Chemical-Resistant Hard Viton® Fluoroelastomer O-Ring Assortments for Straight-Thread Connection.
    Stock a variety of O-rings, so you always have the size you need. The O-rings in these assortments are made for tube fittings with a straight-thread connection--they're also known as Boss O-rings. With a 90A durometer, they’re harder and more durable than standard Viton® fluoroelastomer O-rings. Use them to seal high-pressure parts, such as fuel injectors. They resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. To install, place them behind the threads on a male fitting. As you tighten against a female fitting, the O-ring compresses to form a tight seal.
    No. of
    Pieces
    No. of Sizes
    Included
    Includes
    Specs. Met
    Temp. Range,
    ° F
    Hardness
    Color
    Each
    21220Dash Numbers 901-914, 916, 918, 920, 924, 928, 932ASTM D2000, SAE AS568, SAE J200-15 to 400Durometer 90A (Hard)Black9749K390000000

    Oil-Resistant Buna-N O-Ring Assortments

    Image of Product. Front orientation. 150 Number of Sizes Included. Oil-Resistant Buna-N O-Ring Assortments, 1,110 Pieces.

    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.
    No. of
    Pieces
    No. of Sizes
    Included
    Includes
    Specs. Met
    Temp. Range,
    ° F
    Each
    Durometer 70A (Medium)
     
    Black
    1,110150Dash Numbers 001-046, 110-151, 210-237, 325-338, 901-914, 916, 918, 920, 924, 928, 932ASTM D2000, SAE AS568, SAE J200-25 to 2509000K140000000
     

    Chemical-Resistant Hard Viton® Fluoroelastomer O-Rings for Straight-Thread Connections

    Image of Product. Front orientation. O-Rings. Chemical-Resistant Hard Viton® Fluoroelastomer O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Chemical-Resistant Hard Viton® Fluoroelastomer O-Rings for Straight-Thread Connections.
    Also known as Boss O-rings, these Viton® fluoroelastomer O-rings are made for tube fittings with a straight-thread connection. With a 90A durometer, they’re harder and more durable than standard Viton® fluoroelastomer O-rings. Use them to seal high-pressure parts, such as fuel injectors and heavy duty hydraulic cylinders. They resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. To install, place them behind the threads on a male fitting. As you tighten against a female fitting, the O-ring compresses to form a tight seal. All have shelf life, a cure date, and a traceable lot number printed on the bag.
    Pkg.
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    904
    1/4"0.072"0.351"0.495"Durometer 90A (Hard)ASTM D2000, SAE AS568, SAE J2000 to 400Black259752K1140000000000

    High-Temperature Soft Silicone O-Rings for Straight-Thread Connections

    Image of Product. Bottom orientation. O-Rings. High-Temperature Soft Silicone O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. High-Temperature Soft Silicone O-Rings for Straight-Thread Connections.
    Softer than standard silicone O-rings, these O-rings form a better seal in enclosures, reservoirs, and other low-pressure equipment. They withstand temperatures up to 400° F or higher. Also known as Boss O-rings, they’re made for tube fittings with a straight-thread connection. They resist water, oil, and alcohol, so they’re often used to seal food processing equipment. They’re also FDA compliant for direct contact with food. To install, fit them behind the threads on a male fitting. As you tighten against a female fitting, the O-ring compresses to form a tight seal. All have a cure date and a traceable lot number printed on the bag.
    Pkg.
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Food Industry Std.
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    904
    1/4"0.072"0.351"0.495"Durometer 50A (Soft)ASTM D2000, SAE AS568FDA Compliant 21 CFR 177.2600
    -85 to 400Red101173N6780000000000

    Ultra-Chemical-Resistant Rigid PTFE O-Rings for Straight-Thread Connections

    Image of Product. Front orientation. O-Rings. Ultra-Chemical-Resistant Rigid PTFE O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Ultra-Chemical-Resistant Rigid PTFE O-Rings for Straight-Thread Connections.
    Also known as Boss O-rings, these O-rings are used in tube fittings with a straight-thread connection. Made of PTFE, they withstand extreme temperatures and harsh chemicals such as fluorinated solvents, ethanol, and acetone. They’re also rigid, which makes them more difficult to install than flexible O-rings. These O-rings are FDA compliant for direct contact with food. You’ll find them in pump shafts, mixing tanks, and other equipment that processes chemicals or pharmaceuticals. Install them behind the threads on a male fitting. As you tighten against a female fitting, the O-ring compresses to form a tight seal. All have a cure date and a traceable lot number on the bag.
    Fractional
    Pkg.
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Wd.
    ID
    OD
    Hardness
    Specs.
    Met
    Food Industry Std.
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    904
    1/4"5/6423/641/20.072"0.351"0.495"Durometer 55D (Hard)SAE AS568FDA Compliant 21 CFR 177.1550
    -300 to 500White256613N1400000000000

    Chemical-Resistant Viton® Fluoroelastomer O-Ring Assortments

    Image of Product. Front orientation. 150 Number of Sizes Included. Chemical-Resistant Viton® Fluoroelastomer O-Ring Assortments, 1,110 Pieces.

    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.
    No. of
    Pieces
    No. of Sizes
    Included
    Includes
    Specs. Met
    Temp. Range,
    ° F
    Each
    Durometer 75A (Medium)
     
    Black
    1,110150Dash Numbers 001-046, 110-151, 210-237, 325-338, 901-914, 916, 918, 920, 924, 928, 932ASTM D2000, SAE AS568, SAE J200-15 to 4009465K110000000
     

    Chemical-Resistant Mil. Spec. Viton® Fluoroelastomer O-Rings for Straight-Thread Connections

    Image of Product. Front orientation. O-Rings. Chemical-Resistant Mil. Spec. Viton® Fluoroelastomer O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Chemical-Resistant Mil. Spec. Viton® Fluoroelastomer O-Rings for Straight-Thread Connections.
    Also known as Boss O-rings, these O-rings are made for tube fittings with a straight-thread connection. They’re made of Viton® fluoroelastomer that meets MIL-R-83248 performance standards. Often used in fuel or hydraulic systems, they resist chemicals such as benzene, butyl alcohol, and ethylene glycol. Fit these O-rings behind the threads on a male fitting. As you tighten against a female fitting, the O-ring compresses to form a tight seal. All have shelf life, a cure date, and a traceable lot number printed on the bag.
    Pkg.
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Mil. Spec.
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    904
    1/4"0.072"0.351"0.495"Durometer 75A (Medium)ASTM D2000, SAE AS568, SAE J200MIL-R-832485 to 400Black1001201T292000000000000

    Oil- and Abrasion-Resistant Polyurethane O-Rings for Straight-Thread Connections

    Image of Product. Front orientation. O-Rings. Oil- and Abrasion-Resistant Polyurethane O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Oil- and Abrasion-Resistant Polyurethane O-Rings for Straight-Thread Connections.
    Commonly called Boss O-rings, these polyurethane O-rings are for use in tube fittings with a straight-thread connection. They resist mineral oil, motor oil, and ethylene glycol. All have a round profile and are suitable for a wide range of static and dynamic sealing applications. These O-rings are sized to the SAE standard AS568.
    Pkg.
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    904
    1/4"0.072"0.351"0.495"Durometer 70A (Medium)ASTM D2000, SAE AS568, SAE J200-40 to 200Black19558K4730000000000

    Water- and Steam-Resistant EPDM O-Rings for Tube Fittings with Straight-Thread Connection

    Image of Product. Front orientation. O-Rings. Water- and Steam-Resistant EPDM O-Rings for Tube Fittings with Straight-Thread Connection.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Water- and Steam-Resistant EPDM O-Rings for Tube Fittings with Straight-Thread Connection.
    Also known as Boss O-rings, these EPDM O-rings are for use in tube fittings with a straight-thread connection. They resist water, steam, ethanol, and ethylene glycol. All have a round profile and are suitable for a wide range of static and dynamic sealing applications. These O-rings are sized to the SAE standard AS568.
    Pkg.
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    904
    1/4"0.072"0.351"0.495"Durometer 70A (Medium)ASTM D2000, SAE AS568, SAE J200-70 to 250Black909557K43800000000000000000

    Low-Temperature Chemical-Resistant Mil. Spec. Fluorosilicone O-Rings for Straight-Thread Connections

    Image of Product. Front orientation. O-Rings. Low-Temperature Chemical-Resistant Mil. Spec. Fluorosilicone O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Low-Temperature Chemical-Resistant Mil. Spec. Fluorosilicone O-Rings for Straight-Thread Connections.
    Also known as Boss O-rings, these O-rings are made for tube fittings with a straight-thread connection. They’re fluorosilicone, which stays flexible in temperatures as low as -65° F, so they form better seals than Viton® fluoroelastomer O-rings in cold environments. These O-rings withstand ethanol and ethylene glycol. They also meet MIL-R-25988 standards for quality and performance. To install, place them behind the threads on a male fitting. As you tighten against a female fitting, the O-ring compresses to form a tight seal. Shelf life, a cure date, and a traceable lot number are printed on the bag.
    Pkg.
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Mil. Spec.
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    904
    1/4"0.072"0.351"0.495"Durometer 70A (Medium)ASTM D2000, SAE AS568MIL-R-25988-65 to 390Blue103642N140000000000

    Chemical-Resistant Viton® Fluoroelastomer O-Rings for Straight-Thread Connections

    Image of Product. Front orientation. O-Rings. Chemical-Resistant Viton® Fluoroelastomer O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Chemical-Resistant Viton® Fluoroelastomer O-Rings for Straight-Thread Connections.
    Also known as Boss O-rings, these O-rings are made for tube fittings with a straight-thread connection. Made of Viton® fluoroelastomer, they resist a variety of chemicals, including benzene, butyl alcohol, and ethylene glycol. They combine the oil resistance of Buna-N with the heat tolerance of silicone, so they’re often used to seal hydraulic systems or machines that process crude oil. To install, place them behind the threads on a male fitting. As you tighten against a female fitting, the O-ring compresses to form a tight seal. All have shelf life, a cure date, and a traceable lot number printed on the bag.
    Pkg.
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Choose a
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    904
    1/4"0.072"0.351"0.495"Durometer 75A (Medium)ASTM D2000, SAE AS568, SAE J2000 to 400Black, Brown255267T7860000000000

    High-Temperature High-Purity Silicone O-Rings for Straight-Thread Connections

    Image of Product. Bottom orientation. O-Rings. High-Temperature High-Purity Silicone O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. High-Temperature High-Purity Silicone O-Rings for Straight-Thread Connections.
    Also known as boss O-rings, these O-rings are sized to fit straight-thread fittings to prevent leaks. They were first designed for biomedical use, are made of FDA-listed materials, and are USP VI certified. Their high purity makes them a common choice for food and pharmaceutical applications. Made of silicone, they resist heat up to 400° F for use in high-temperature lines. All have a cure date and a traceable lot number printed on the bag. These O-rings are not cleaned and bagged.
    Pkg.
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Food Industry Std.
    USP
    Class
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    904
    1/4"0.072"0.351"0.495"Durometer 70A (Medium)ASTM D2000, SAE AS568, SAE J200FDA Compliant 21 CFR 177.2600
    VI-60 to 400Red509396K423000000000000

    Ultra-Chemical-Resistant DuPont Kalrez 4079 O-Rings for Straight-Thread Connections

    Image of Product. Bottom orientation. O-Rings. Ultra-Chemical-Resistant DuPont Kalrez 4079 O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Ultra-Chemical-Resistant DuPont Kalrez 4079 O-Rings for Straight-Thread Connections.
    Also known as Boss O-rings, these O-rings are made for tube fittings with a straight-thread connection. Made of Kalrez 4079, they 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.
    Each
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    1-9
    10-Up
    904
    1/4"0.072"0.351"0.495"Durometer 75A (Medium)ASTM D2000, SAE AS568, SAE J20030 to 600Black9568K941000000000000

    Water- and Weather-Resistant Neoprene O-Rings for Straight-Thread Connections

    Image of Product. Front orientation. O-Rings. Water- and Weather-Resistant Neoprene O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Water- and Weather-Resistant Neoprene O-Rings for Straight-Thread Connections.
    Also known as boss O-rings, these neoprene O-rings seal straight-thread fittings in valve housings, outdoor enclosures, and saltwater applications. They resist water, UV rays, and mild chemicals, making them good for use both indoors and outdoors. Compared to EPDM O-rings, these neoprene O-rings have better resistance to oil and chemicals. All have shelf life, cure date, and a traceable lot number printed on the bag.
    Pkg.
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    Pkg.
    Qty.
    1-9
    10-Up
    904
    1/4"0.072"0.351"0.495"Durometer 70A (Medium)ASTM D2000, SAE AS568, SAE J200-10 to 170Black9094115K4790000000000

    Ultra-Chemical-Resistant FFKM 4079 O-Rings for Straight-Thread Connections

    Image of Product. Bottom orientation. O-Rings. Ultra-Chemical-Resistant FFKM 4079 O-Rings for Straight-Thread Connections.
    Image of Attribute. Front orientation. CrossSection view. Contains Annotated. O-Rings. Ultra-Chemical-Resistant FFKM 4079 O-Rings for Straight-Thread Connections.
    The same chemical and heat resistance as Kalrez 4079 without the brand name. These FFKM O-rings resist a wide range of chemicals, including acetone, methyl ethyl ketone (MEK), potassium hydroxide, and most acids—even at scorching temperatures of 600° F. Also known as boss O-rings, they’re sized to fit straight-thread fittings to prevent leaks. Use them to seal fittings in high-temperature chemical lines. All have cure date and a traceable lot number printed on the bag.
    Each
    Dash
    No.
    For Tube
    OD
    Wd.
    ID
    OD
    Hardness
    Specs. Met
    Temp. Range,
    ° F
    Color
    1-9
    10-Up
    904
    1/4"0.072"0.351"0.495"Durometer 75A (Medium)ASTM D2000, SAE AS568, SAE J20015 to 600Black8714N14000000000000
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