McMaster-Carr logo
    Filter by
    System of Measurement
    Thread Pitch
    Industrial Info Snippet
    Attribute Image
    Width
    Attribute Image
    Cap Nut Profile
    Thread Type
    Specifications Met
    Drive Style
    Industrial Info Snippet
    Fastener Strength Rating
    Fastener Strength Grade/Class
    Industrial Info Snippet
    Thread Spacing
    Industrial Info Snippet
    U.S.–Mexico–Canada Agreement (USMCA) Qualifying
    Export Control Classification Number (ECCN)
    Industrial Info Snippet
    DFARS Specialty Metals
    Industrial Info Compare
    Thread Fit
    Industrial Info Snippet
    Attribute Image
    Maximum Temperature
    Forward
    Enter e-mail addresses in the fields below
    Message
    Cancel
    Print
    How can we improve?
    Comments
    E-mail address (if you would like a response)
    7 Products

    Performance

    Locking Type

    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.
    Stainless Steel
    Image of Product. Front orientation. Cap Nuts. Cap Nuts.
    18-8 Stainless Steel—The choice for wet and outdoor environments, these nuts resist rust. However, they won't hold up to the harsh chemicals that 316 stainless steel can.
    Highly Corrosion-Resistant 316 Stainless Steel—Our most corrosion-resistant cap nuts, these hold up in just about any environment. They won't degrade from exposure to weather, salt water, and most chemicals.
    Material Certificate Icon
    Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.
    Pkg.
    Thread
    Size
    Thread
    Dp., mm
    Wd.,
    mm
    Ht.,
    mm
    Specs.
    Met
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    18-8 Stainless Steel
    M5 × 0.8 mm4.5810DIN 15872594000A037000000000000000
     
    Highly Corrosion-Resistant 316 Stainless Steel
    M5 × 0.8 mm4.5810DIN 15872595514A103000000000000
     
    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.
    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., mm
    Wd.,
    mm
    Ht.,
    mm
    Specs.
    Met
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    Zinc-Plated Steel
    M5 × 0.8 mm3.7810DIN 15875091880A037000000000000000000
     
    Chrome-Plated Steel
    M5 × 0.8 mm5.6810DIN 1587591982A22500000000000000
     
    Plastic
    Image of Product. Front orientation. Cap Nuts. Cap Nuts.
    Nylon 6/6—Slippery and abrasion resistant, these nuts thread on smoothly and stand up to daily wear and tear. Nylon will swell and weaken when exposed to moisture, so it's best for dry environments.
    Pkg.
    Thread
    Size
    Wd.,
    mm
    Ht.,
    mm
    Temp. Range,
    ° F
    Choose a Color
    Pkg.
    Qty.
    1-9
    10-49
    50-Up
    Nylon 6/6
    M5 × 0.8 mm810-40 to 185Black, Off-White10090527A510000000000000000000
     

    Cap Nuts with Threadlocker

    Image of Product. Front orientation. Contains Annotated, Border. Cap Nuts. Cap Nuts with Threadlocker.
    These nuts not only conceal and protect protruding screw threads, they also resist loosening from mild vibration. They have a nylon patch bonded to their threads that grips screws for a tighter hold than standard cap nuts. They’re reusable a handful of times, but the patch’s holding power decreases with each use. Also known as acorn nuts, they have a smooth, rounded head that creates a finished look.
    Material Certificate Icon
    Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.
    Stainless Steel
    18-8 Stainless Steel—The choice for wet and outdoor environments, these nuts resist rust. However, they won't hold up to the harsh chemicals that 316 stainless steel can.
    Thread
    Size
    Thread
    Dp., mm
    Wd.,
    mm
    Ht.,
    mm
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    M5 × 0.8 mm5.6810DIN 1587590428A110000000
     

    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.
    Thread
    Size
    Thread
    Dp., mm
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M5 × 0.8 mm3.5810.5Class 6
    		DIN 9862452590582A11200000
     
    back to top