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    6 Products

    Coupling Nuts

    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
    10-49
    50-Up
    Zinc-Plated Steel
    M18 × 2.5 mm5427Fully ThreadedDIN 633493355A550000000000000000000
     
    Black-Oxide Steel
    M18 × 2.5 mm5427Fully ThreadedDIN 633493020A107000000000000000
     
    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.
    Material Certificate Icon
    Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.
    Each
    Thread Size
    Lg.,
    mm
    Wd.,
    mm
    Fastener Strength
    Grade/Class
    Threading
    Specs. Met
    1-9
    10-49
    50-Up
    Zinc-Plated Steel
    M18 × 2.5 mm5427Class 8
    		Fully ThreadedASME B18.2.2, DIN 633490009A233000000000000000000
     
    Black-Oxide Steel
    M18 × 2.5 mm5427Class 8
    		Fully ThreadedASME B18.2.2, DIN 633490082A119000000000000000
     
    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.
    Highly 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
    Specs. Met
    1-9
    10-49
    50-Up
    18-8 Stainless Steel
    M18 × 2.5 mm5427Fully ThreadedASME B18.2.2, DIN 633493590A312000000000000000000
     
    Highly Corrosion-Resistant 316 Stainless Steel
    M18 × 2.5 mm5427Fully ThreadedDIN 633490111A337000000000000000
     
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