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    151 Products

    Cap Nuts

    Conceal and protect protruding screw threads while fastening parts together. These nuts help prevent damage to surrounding materials and reduce injuries. Also known as acorn nuts, they have a smooth, rounded head that creates a finished look.
    Low-Strength Steel
    Image of Product. Front orientation. Cap Nuts. Cap Nuts.
    Rated Grade 2, Class 6, or lower, these nuts are about half as strong as medium-strength steel nuts. They are suitable for light duty fastening applications, such as securing access panels. Use them with screws that have a similar strength rating to avoid stripping threads during installation.
    Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.
    Black Corrosion-Resistant-Coated Steel—Combines a finished appearance with the rust resistance of stainless steel. The coating has been tested to extreme standards, including 1,000 hours of salt spray resistance, to hold up in wet and outdoor environments. Also known as black luster.
    Nickel-Plated Steel—This plating resists salt water and chemicals better than zinc plating and is less likely to wear off. It also has a bright, polished appearance.
    Chrome-Plated Steel—The brightest, shiniest finish we offer, this plating has a mirror-like appearance that is often used in decorative applications. It resists salt water and chemicals better than zinc plating and is less likely to wear off.
    Pkg.
    Thread Size
    Thread
    Dp.
    Wd.
    Ht.
    Specs.
    Met
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    Zinc-Plated Steel
    2-56
    		5/32"1/4"1/4"—25000000000000000000000000
    3-48
    		5/32"1/4"1/4"—10000000000000000000000
    4-40
    		5/32"1/4"1/4"—50000000000000000000000000
    4-48
    		5/32"1/4"1/4"—10000000000000000000000
    5-40
    		5/32"5/16"11/32"—10000000000000000000000
    6-32
    		5/32"5/16"11/32"—50000000000000000000000000
    6-40
    		5/32"5/16"11/32"—10000000000000000000000
    8-32
    		5/32"5/16"11/32"—50000000000000000000000000
    8-36
    		5/32"5/16"11/32"—10000000000000000000000
    10-24
    		3/16"3/8"13/32"—50000000000000000000000000
    10-32
    		3/16"3/8"13/32"—50000000000000000000000000
    1/4"-20
    		1/4"7/16"15/32"—250000000000000000000000
    1/4"-28
    		1/4"7/16"15/32"—250000000000000000000000
    5/16"-18
    		5/16"1/2"17/32"—25000000000000000000000000
    5/16"-24
    		5/16"1/2"17/32"—25000000000000000000000000
    3/8"-16
    		3/8"9/16"5/8"—25000000000000000000000000
    3/8"-24
    		3/8"9/16"5/8"—25000000000000000000000000
    7/16"-14
    		7/16"5/8"11/16"—20000000000000000000000000
    7/16"-20
    		7/16"5/8"11/16"—20000000000000000000000000
    1/2"-13
    		1/2"3/4"13/16"—1000000000000000000000000
    1/2"-20
    		1/2"3/4"13/16"—1000000000000000000000000
    5/8"-11
    		5/8"15/16"1"—500000000000000000000000
    5/8"-18
    		5/8"15/16"1"—500000000000000000000000
    3/4"-10
    		3/4"1 1/16"1 5/32"—1000000000000000000000
    3/4"-16
    		3/4"1 1/16"1 5/32"—1000000000000000000000
    7/8"-9
    		7/8"1 1/4"1 23/64"—1000000000000000000000
    7/8"-14
    		7/8"1 1/4"1 23/64"—1000000000000000000000
    1"-8
    		1"1 7/16"1 35/64"—1000000000000000000000
    1"-14
    		1"1 7/16"1 35/64"—1000000000000000000000
    1 1/4"-7
    		1 1/4"1 13/16"1 61/64"—1000000000000000000000000
    1 1/4"-12
    		1 1/4"1 13/16"1 61/64"—1000000000000000000000000
    M4 × 0.7 mm5.3 mm7 mm8 mmDIN 158750000000000000000000000000
    M5 × 0.8 mm3.7 mm8 mm10 mmDIN 158750000000000000000000000000
    M6 × 1 mm7.7 mm10 mm12 mmDIN 158750000000000000000000000000
    M8 × 1.25 mm10.7 mm13 mm15 mmDIN 158725000000000000000000000000
    M10 × 1.5 mm12.7 mm17 mm18 mmDIN 1587100000000000000000000000
    M12 × 1.75 mm15.7 mm19 mm22 mmDIN 158710000000000000000000000000
     
    Black Corrosion-Resistant-Coated Steel
    4-40
    		5/32"1/4"1/4"—10000000000000000000000000
    6-32
    		5/32"5/16"11/32"—10000000000000000000000000
    8-32
    		5/32"5/16"11/32"—10000000000000000000000000
    10-24
    		3/16"3/8"13/32"—5000000000000000000000
    10-32
    		3/16"3/8"13/32"—5000000000000000000000
    1/4"-20
    		1/4"7/16"15/32"—5000000000000000000000
    5/16"-18
    		5/16"1/2"17/32"—50000000000000000000000
    3/8"-16
    		3/8"9/16"5/8"—1000000000000000000000
    7/16"-14
    		7/16"5/8"11/16"—1000000000000000000000
    1/2"-13
    		1/2"3/4"13/16"—1000000000000000000000
    9/16"-12
    		9/16"7/8"15/16"—1000000000000000000000
    5/8"-11
    		5/8"15/16"1"—1000000000000000000000
     
    Nickel-Plated Steel
    6-32
    		5/32"5/16"1/4"—1000000000000000000000000
    8-32
    		5/32"5/16"1/4"—1000000000000000000000000
    10-24
    		3/16"3/8"5/16"—100000000000000000000000
    10-32
    		3/16"3/8"5/16"—100000000000000000000000000
    1/4"-20
    		1/4"7/16"3/8"—100000000000000000000000000
    5/16"-18
    		5/16"9/16"15/32"—50000000000000000000000000
    3/8"-16
    		3/8"5/8"1/2"—25000000000000000000000
    1/2"-13
    		1/2"3/4"9/16"—25000000000000000000000000
    5/8"-11
    		5/8"15/16"13/16"—10000000000000000000000000
    3/4"-10
    		3/4"1 1/8"1 1/8"—1000000000000000000000
     
    Chrome-Plated Steel
    M4 × 0.7 mm3.9 mm7 mm8 mmDIN 1587500000000000000000000000
    M5 × 0.8 mm5.6 mm8 mm10 mmDIN 1587500000000000000000000000
    M6 × 1 mm5.7 mm10 mm12 mmDIN 15875000000000000000000000000
    M8 × 1.25 mm8.2 mm13 mm15 mmDIN 15871000000000000000000000
    M10 × 1.5 mm9.7 mm17 mm18 mmDIN 15871000000000000000000000
    M12 × 1.75 mm12.2 mm19 mm22 mmDIN 15871000000000000000000000
     
    Medium-Strength Steel
    Image of Product. Front orientation. Cap Nuts. Cap Nuts.
    About twice as strong as low-strength steel, these Grade 5 nuts fasten most machinery and equipment. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.
    Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.
    Black Corrosion-Resistant-Coated Steel—Combines a finished appearance with the rust resistance of stainless steel. The coating has been tested to extreme standards, including 1,000 hours of salt spray resistance, to hold up in wet and outdoor environments. Also known as black luster.
    Pkg.
    Thread
    Size
    Thread
    Dp.
    Wd.
    Ht.
    Fastener Strength
    Grade/Class
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    Zinc-Plated Steel
    1/4"-20
    		1/4"7/16"15/32"SAE Grade 5
    		10000000000000000000000000
    5/16"-18
    		5/16"1/2"17/32"SAE Grade 5
    		100000000000000000000000
    3/8"-16
    		3/8"9/16"5/8"SAE Grade 5
    		10000000000000000000000000
    1/2"-13
    		1/2"3/4"13/16"SAE Grade 5
    		5000000000000000000000000
    5/8"-11
    		5/8"15/16"1"SAE Grade 5
    		1000000000000000000000
    3/4"-10
    		3/4"1 1/8"1 5/32"SAE Grade 5
    		1000000000000000000000
    7/8"-9
    		7/8"1 1/4"1 23/64"SAE Grade 5
    		1000000000000000000000000
    1"-8
    		1"1 1/2"1 35/64"SAE Grade 5
    		1000000000000000000000000
     
    Black Corrosion-Resistant-Coated Steel
    1/4"-20
    		1/4"7/16"15/32"SAE Grade 5
    		1000000000000000000000
    5/16"-18
    		5/16"1/2"17/32"SAE Grade 5
    		1000000000000000000000
    3/8"-16
    		3/8"9/16"5/8"SAE Grade 5
    		1000000000000000000000
    1/2"-13
    		1/2"3/4"13/16"SAE Grade 5
    		1000000000000000000000000
     
    High-Strength Steel
    Image of Product. Front orientation. Cap Nuts. Cap Nuts.
    Rated Grade 8 or Class 10, these nuts are about 25% stronger than medium-strength steel nuts. They are commonly used to fasten components in valves, pumps, motors, and other high-stress applications. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.
    Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.
    Black Corrosion-Resistant-Coated Steel—Combines a finished appearance with the rust resistance of stainless steel. The coating has been tested to extreme standards, including 1,000 hours of salt spray resistance, to hold up in wet and outdoor environments. Also known as black luster.
    Pkg.
    Thread Size
    Thread
    Dp.
    Wd.
    Ht.
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    Zinc-Plated Steel
    1/4"-20
    		1/4"7/16"15/32"SAE Grade 8
    		—1000000000000000000000000000
    5/16"-18
    		5/16"1/2"17/32"SAE Grade 8
    		—10000000000000000000000000
    3/8"-16
    		3/8"9/16"5/8"SAE Grade 8
    		—10000000000000000000000000
    1/2"-13
    		1/2"3/4"13/16"SAE Grade 8
    		—1000000000000000000000
    5/8"-11
    		5/8"15/16"1"SAE Grade 8
    		—1000000000000000000000
    3/4"-10
    		3/4"1 1/8"1 5/32"SAE Grade 8
    		—1000000000000000000000
    7/8"-9
    		7/8"1 1/4"1 23/64"SAE Grade 8
    		—1000000000000000000000000
    1"-8
    		1"1 1/2"1 35/64"SAE Grade 8
    		—1000000000000000000000000
    M6 × 1 mm5.7 mm10 mm12 mmClass 10DIN 15875000000000000000000000000
    M8 × 1.25 mm8.2 mm13 mm15 mmClass 10DIN 15875000000000000000000000000
    M10 × 1.5 mm9.7 mm17 mm18 mmClass 10DIN 15871000000000000000000000
    M12 × 1.75 mm12.2 mm19 mm22 mmClass 10DIN 158710000000000000000000000
     
    Black Corrosion-Resistant-Coated Steel
    1/4"-20
    		1/4"7/16"15/32"SAE Grade 8
    		—1000000000000000000000
    5/16"-18
    		5/16"1/2"17/32"SAE Grade 8
    		—1000000000000000000000
    3/8"-16
    		3/8"9/16"5/8"SAE Grade 8
    		—1000000000000000000000
    1/2"-13
    		1/2"3/4"13/16"SAE Grade 8
    		—1000000000000000000000000
     

    Nylon-Insert Cap Nuts

    Get the protection of a cap nut with the vibration resistance of a locknut. These nuts not only conceal protruding screw threads, they also have a nylon insert that grips the screw to prevent loosening from moderate vibration. However, the insert may become brittle if exposed to high temperatures. Nuts are reusable a handful of times, but their holding power decreases with each use.
    Low-Strength Steel
    Image of Product. Bottom orientation. Cap Nuts. Nylon-Insert Cap Nuts.
    Rated Grade 2, Class 6, or lower, these nuts are about half as strong as medium-strength steel nuts. Use them with screws that have a similar strength rating to avoid stripping threads during installation.
    Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.
    Steel—Best for dry environments since moisture will cause these nuts to rust.
    Nylon 6/6 Cap—The nylon cap on these nuts is softer than metal, so it's less likely to scratch surrounding surfaces or parts.
    Thread Size
    Thread
    Dp.
    Wd.
    Ht.
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M4 × 0.7 mm2.3 mm7 mm9.6 mmClass 6DIN 98624550000000000000000
    M5 × 0.8 mm3.5 mm8 mm10.5 mmClass 6DIN 986245250000000000000
    M6 × 1 mm3.9 mm10 mm12 mmClass 6DIN 986245250000000000000
    M8 × 1.25 mm5.2 mm13 mm14 mmClass 6DIN 9862452500000000000000
    M10 × 1.5 mm6.4 mm16 mm18 mmClass 6DIN 9862451000000000000000
    M12 × 1.75 mm8.3 mm18 mm23 mmClass 6DIN 98624550000000000000
    M16 × 2 mm11.3 mm24 mm28 mmClass 6DIN 98624510000000000000
    M20 × 2.5 mm13.5 mm30 mm35 mmClass 6DIN 98624510000000000000
     
    Zinc-Plated Steel with Nylon 6/6 Cap
    8-32
    		9/64"11/32"23/64"SAE Grade 2
    		—250250000000000000
    10-24
    		9/64"3/8"23/64"SAE Grade 2
    		—250250000000000000
    10-32
    		9/64"3/8"23/64"SAE Grade 2
    		—250250000000000000
    1/4"-20
    		7/32"7/16"31/64"SAE Grade 2
    		—250250000000000000
    5/16"-18
    		1/4"1/2"1/2"SAE Grade 2
    		—250100000000000000
    3/8"-16
    		21/64"9/16"5/8"SAE Grade 2
    		—2502500000000000000
     
    Steel with Nylon 6/6 Cap
    8-32
    		9/64"11/32"23/64"SAE Grade 2
    		—250250000000000000
    10-32
    		9/64"3/8"23/64"SAE Grade 2
    		—250250000000000000
    1/4"-20
    		7/32"7/16"31/64"SAE Grade 2
    		—250250000000000000
    1/4"-28
    		7/32"7/16"31/64"SAE Grade 2
    		—250250000000000000
    5/16"-24
    		1/4"1/2"1/2"SAE Grade 2
    		—250250000000000000
    3/8"-24
    		21/64"9/16"5/8"SAE Grade 2
    		—2502500000000000000
     
    Medium-Strength Steel
    Image of Product. Bottom orientation. Cap Nuts. Nylon-Insert Cap Nuts.
    About twice as strong as low-strength steel, these Grade 5 nuts fasten most machinery and equipment. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.
    Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.
    Nylon 6/6 Cap—The nylon cap on these nuts is softer than metal, so it's less likely to scratch surrounding surfaces or parts.
    Thread
    Size
    Thread
    Dp.
    Wd.
    Ht.
    Fastener Strength
    Grade/Class
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel with Nylon 6/6 Cap
    3/8"-24
    		21/64"9/16"5/8"SAE Grade 5
    		25010000000000000000
     

    High-Heavy-Profile Cap Nuts

    Image of Product. Bottom orientation. Cap Nuts. High-Heavy-Profile Cap Nuts.
    20% wider and taller than standard cap nuts, these have high, flat sides so your wrench won't slip off as you tighten. They cover screws to protect the threads and to prevent damage to surrounding materials. Also known as acorn nuts, they have a smooth, rounded head to create a finished look.
    Steel
    Black-Oxide Steel—Typically chosen for their appearance, these nuts have a dark, matte coating. They offer minimal corrosion resistance, so they're best for dry environments.
    Thread
    Size
    Thread
    Dp.
    Wd.
    Ht.
    Each
    Black-Oxide Steel
    1/4"-20
    		3/8"5/8"5/8"00000000000000
    5/16"-18
    		3/8"5/8"5/8"0000000000000
    3/8"-16
    		15/32"3/4"3/4"0000000000000
    1/2"-13
    		19/32"7/8"15/16"0000000000000
    5/8"-11
    		25/32"1 1/16"1 3/16"0000000000000
    3/4"-10
    		29/32"1 1/4"1 3/8"00000000000000
    7/8"-9
    		1 1/16"1 3/8"1 5/8"00000000000000
     

    Retaining Caps

    Image of Product. 400 Series Stainless Steel. Front orientation. Protective Caps. Retaining Caps.

    400 Series

    Stainless

    Steel

    Image of Product. 1050 Spring Steel. Bottom orientation. Protective Caps. Retaining Caps.

    1050 Spring Steel

    Image of Product. Plastic. Bottom orientation. Protective Caps. Retaining Caps.

    Plastic

    Use these caps to hold components in place and protect shaft ends. Install these caps with a hammer or push them into place by hand.
    Corrosion-Resistant Coated—Corrosion-resistant-coated finish is more corrosion resistant in wet environments than zinc-plated finish. Also known as black luster.
    Nickel Plated—Nickel-plated finish has excellent corrosion resistance and a decorative appearance.
    Zinc Plated—Zinc-plated finish is corrosion resistant in wet environments.
    For
    OD
    OD
    Ht.
    Insert
    Material
    Min.
    Hardness
    Temp. Range,
    ° F
    Pkg.
    Qty.
    Pkg.
    Black Corrosion-Resistant-Coated 1050 Spring Steel
    1/4"9/16"7/32"SteelNot Rated—500000000000000
    5/16"5/8"1/4"SteelNot Rated—50000000000000
    3/8"3/4"9/32"SteelNot Rated—500000000000000
    1/2"15/16"21/64"SteelNot Rated—500000000000000
     
    Nickel-Plated 1050 Spring Steel
    1/4"1/2"7/32"SteelRockwell C13—250000000000000
    3/8"3/4"9/32"SteelRockwell C13—250000000000000
     
    Zinc-Plated 1050 Spring Steel
    5/16"9/16"19/64"SteelRockwell C44—250000000000000
    1/2"15/16"21/64"SteelRockwell C38—100000000000000
    5/8"1 3/16"27/64"SteelRockwell C38—100000000000000
     
    Black Plastic
    5/32"21/32"23/64"SteelRockwell C45-90 to 1505000000000000000
    3/16"21/32"23/64"SteelRockwell C45-90 to 1505000000000000000
    1/4"27/32"23/64"SteelRockwell C45-90 to 1505000000000000000
    5/16"27/32"29/64"SteelRockwell C45-90 to 1502500000000000000
    3/8"55/64"15/32"SteelRockwell C45-90 to 150250000000000000
    7/16"53/64"7/16"SteelRockwell C45-90 to 150100000000000000
    1/2"1 5/16"41/64"SteelRockwell C45-90 to 150100000000000000
    5/8"1 5/16"41/64"SteelRockwell C45-90 to 150100000000000000
     
    White Plastic
    1/8"21/32"23/64"SteelRockwell C45-90 to 1501000000000000000
    3/16"21/32"11/32"SteelRockwell C45-90 to 150250000000000000
    3/8"55/64"15/32"SteelRockwell C45-90 to 150250000000000000
     
    Red Plastic
    5/16"55/64"15/32"SteelRockwell C45-90 to 150250000000000000
     

    Distorted-Thread Cap Nuts

    Image of Product. Bottom orientation. Cap Nuts. Distorted-Thread Cap Nuts.
    For a stronger hold than nylon-insert cap nuts, these have irregularly shaped threads that grip the screw to resist loosening. The threads prevent the nut from backing out in high-vibration applications, but they also increase the effort to install and remove. To get these nuts off, you may need special tools, such as an impact wrench or propane torch. They have a smooth, rounded head that conceals and protects protruding screw threads while creating a finished look. Nuts are not reusable.
    Low-Strength Steel
    Rated Grade 2, Class 6, or lower, these nuts are about half as strong as medium-strength steel nuts. Use them with screws that have a similar strength rating to avoid stripping threads during installation.
    Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.
    Thread
    Size
    Thread
    Dp.
    Wd.
    Ht.
    Fastener Strength
    Grade/Class
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    6-32
    		5/32"5/16"11/32"SAE Grade 2
    		50000000000000000
    8-32
    		5/32"5/16"11/32"SAE Grade 2
    		5000000000000000
    10-24
    		3/16"3/8"13/32"SAE Grade 2
    		2500000000000000
    10-32
    		3/16"3/8"13/32"SAE Grade 2
    		2500000000000000
    1/4"-20
    		19/64"7/16"15/32"SAE Grade 2
    		5000000000000000
    5/16"-18
    		23/64"1/2"17/32"SAE Grade 2
    		2500000000000000
    3/8"-16
    		27/64"9/16"5/8"SAE Grade 2
    		2500000000000000
    1/2"-13
    		1/2"3/4"13/16"SAE Grade 2
    		500000000000000
     

    Cap Nut Assortments

    Image of Product. Front orientation. Cap Nuts. Cap Nut Assortments.
    Image of Product. Front orientation. ZoomedIn view. Cap Nuts. Cap Nut Assortments.
    With a range of sizes on hand, you can use these assortments to conceal and protect protruding screw threads while fastening a variety of parts. Also known as acorn nuts, they have a smooth, rounded head that creates a finished look.
    Nickel-Plated Steel—This plating resists salt water and chemicals better than zinc plating and is less likely to wear off. It also has a bright, polished appearance.
    Thread Size
    No. of
    Pieces
    Container
    Type
    Each
    Nickel-Plated Steel
    6-32, 8-32, 10-32, 1/4"-20, 5/16"-18, 3/8"-16
    		200Plastic Box000000000000000
     
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