McMaster-Carr logo
    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)
    11 Products

    Coupling Nuts
    3D CAD models available

    Also known as extension nuts, these are commonly used to connect lengths of threaded rod and join threaded parts.
    Low-Strength Steel
    Image of Product. Front orientation. Coupling Nuts. Coupling Nuts.
    Rated Grade 2 or lower, these are about half as strong as medium-strength steel coupling nuts. Use them with threaded rods that have a comparable 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-Oxide Steel—A dark, matte coating creates a finished look. Nuts offer minimal corrosion resistance, so they're best for dry environments.
    Each
    Thread
    Size
    Lg.,
    mm
    Wd.,
    mm
    Threading
    Specs.
    Met
    1-9
    10-Up
    Zinc-Plated Steel
    M24 × 3 mm7236Fully ThreadedDIN 6334000000000000000000000
     
    Black-Oxide Steel
    M24 × 3 mm6438Fully Threaded__0000000000000000000
     
    Medium-Strength Steel
    Image of Product. Front orientation. Coupling Nuts. Coupling Nuts.
    These Grade 5 or Class 8 nuts are about twice as strong as low-strength steel coupling nuts. Use them with threaded rods that have a comparable 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-Oxide Steel—A dark, matte coating creates a finished look. Nuts offer minimal corrosion resistance, so they're best for dry environments.
    Each
    Thread
    Size
    Lg.,
    mm
    Wd.,
    mm
    Fastener Strength
    Grade/Class
    Threading
    Specs. Met
    1-9
    10-Up
    Zinc-Plated Steel
    M24 × 3 mm7236ISO Class 8
    		Fully ThreadedDIN 6334000000000000000000000
     
    Black-Oxide Steel
    M24 × 3 mm7236ISO Class 8
    		Fully ThreadedASME B18.2.2, DIN 63340000000000000000000
     
    High-Strength Steel
    Image of Product. Front orientation. Coupling Nuts. Coupling Nuts.
    Rated Grade 8 or Class 10, these are about 25% stronger than medium-strength steel coupling nuts. Use them with threaded rods that have a comparable 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.
    Each
    Thread
    Size
    Lg.,
    mm
    Wd.,
    mm
    Fastener Strength
    Grade/Class
    Threading
    Specs.
    Met
    1-9
    10-Up
    Zinc-Plated Steel
    M24 × 3 mm7236ISO Class 10
    		Fully ThreadedDIN 6334000000000000000000000
     
    Steel
    M24 × 3 mm7236ISO Class 10
    		Fully ThreadedDIN 63340000000000000000000
     
    Corrosion-Resistant Stainless Steel
    Image of Product. Front orientation. Coupling Nuts. Coupling 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.
    Super-Corrosion-Resistant 316 Stainless Steel—The most corrosion-resistant stainless steel coupling nuts we offer, these hold up in just about any environment. They won't degrade from exposure to weather, salt water, and most chemicals.
    Each
    Thread
    Size
    Lg.,
    mm
    Wd.,
    mm
    Threading
    Min. Thread
    Lg., mm
    Specs. Met
    1-9
    10-Up
    18-8 Stainless Steel
    M24 × 3 mm7236Fully Threaded__ASME B18.2.2, DIN 6334000000000000000000000
    M24 × 3 mm14441Partially Threaded24__000000000000000000000
     
    Super-Corrosion-Resistant 316 Stainless Steel
    M24 × 3 mm7236Fully Threaded__DIN 63340000000000000000000
     
    Brass
    Image of Product. Front orientation. Coupling Nuts. Coupling Nuts.
    Brass—With a warm, polished look, these nuts are often chosen for their appearance. Similar to 18-8 stainless steel, brass is corrosion resistant enough to stand up to wet environments. It is also softer than other metals, so it's easier to thread together.
    Each
    Thread
    Size
    Lg.,
    mm
    Wd.,
    mm
    Threading
    1-9
    10-Up
    Brass
    M24 × 3 mm7236Fully Threaded000000000000000000000
     

    High-Profile Hex Nuts
    3D CAD models available

    Slightly taller than standard-profile hex nuts, these have a larger gripping area so your wrench or socket won't slip off as you tighten them. They're often used in vehicles and machinery where fasteners can be difficult to reach.
    Medium-Strength Steel
    Image of Product. Front orientation. Hex Nuts. High-Profile Hex Nuts.
    These Grade 5 or Class 8 nuts are your go-to for fastening 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.
    Thread
    Size
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M24 × 3 mm3624ISO Class 8
    		100000000000000
     
    back to top