McMaster-Carr logo
    Filter by
    System of Measurement
    Thread Size
    Industrial Info Compare
    Thread Pitch
    Industrial Info Snippet
    Attribute Image
    Thread Spacing
    Industrial Info Compare
    Nut Type
    Industrial Info Compare
    Hex Nut Profile
    Industrial Info Compare
    Length
    Thread Direction
    Thread Type
    Fastener Strength Rating
    Drive Style
    Industrial Info Snippet
    Export Control Classification Number (ECCN)
    Industrial Info Snippet
    DFARS Specialty Metals
    Industrial Info Compare
    Locking Type
    Hardness
    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)
    12 Products
    About Hex Nuts
    industrial info icon

    Choose a hex nut with the right profile, material, and strength for your application.

    Hex Nuts

    Image of Product. Front orientation. Hex Nuts. Hex Nuts.
    The most commonly used hex nuts, these are suitable for fastening most machinery and equipment.
    Medium-Strength Steel
    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.
    Black-Oxide Steel—Typically chosen for their appearance, these nuts have a dark, matte coating to create a finished look. They offer minimal corrosion resistance, so they're best for dry environments.
    Steel—Best for dry environments since moisture will cause these nuts to rust.
    Thread
    Size
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M39 × 4 mm6031ISO Class 8
    		DIN 934100000000000000
     
    Black-Oxide Steel
    M39 × 4 mm6031ISO Class 8
    		DIN 934100000000000000
     
    Steel
    M39 × 2 mm6031ISO Class 8
    		DIN 934100000000000000
    M39 × 3 mm6031ISO Class 8
    		DIN 934100000000000000
    M39 × 4 mm6031ISO Class 8
    		DIN 93410000000000000
     
    Extreme-Strength Steel
    These nuts are about 20% stronger than high-strength steel nuts. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.
    Steel—Best for dry environments since moisture will cause these nuts to rust.
    Thread
    Size
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Steel
    M39 × 4 mm6031ISO Class 12
    		DIN 9341000000000000000
     
    Corrosion-Resistant Stainless Steel
    Highly-Corrosion-Resistant 316 Stainless Steel—Superior to 18-8 stainless steel, these nuts won't degrade when exposed to harsh weather, salt water, and most chemicals.
    Thread
    Size
    Wd.,
    mm
    Ht.,
    mm
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Highly-Corrosion-Resistant 316 Stainless Steel
    M39 × 4 mm6031DIN 9341000000000000000
     

    Threaded Rods

    Image of Product. Front orientation. Threaded Rods. Threaded Rods.
    Anchor, connect, or hang components in a wide variety of applications, from mounting I-beams to suspending light fixtures.
    High-Strength Steel
    With a tensile strength of 150,000 psi, these rods are strong enough to stabilize steel frameworks and structural supports, such as I-beams. They are about 25% stronger than medium-strength steel rods. To avoid stripped threads during installation, make sure your nuts are also high-strength steel.
    Steel—Best for dry environments since moisture will cause these rods to rust.
    Lg.,
    m
    Tensile Strength,
    psi
    Fastener Strength
    Grade/Class
    Hardness
    Specs.
    Met
    Each
    Steel
     
    M39 × 4 mm
    1150,000ISO Class 10.9
    		Rockwell C32DIN 976000000000000000
     

    Heavy-Profile Hex Nuts

    Image of Product. Front orientation. Hex Nuts. Heavy-Profile Hex Nuts.
    About 10% wider and taller than standard-profile hex nuts, these handle heavier loads by distributing them over a larger area.
    Extreme-Strength Steel
    These nuts are about 20% stronger than high-strength steel nuts. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.
    Steel—Best for dry environments since moisture will cause these nuts to rust.
    Thread
    Size
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Steel
    M39 × 4 mm6539ASTM Grade 2H
    		ASTM A194
    		1000000000000000
     

    Thin-Profile Hex Nuts

    Image of Product. Front orientation. Hex Nuts. Thin-Profile Hex Nuts.
    About half the height of standard-profile nuts, these fit in spaces with low clearance. You can also use them as jam nuts by threading them against another hex nut to hold it in place.
    Medium-Strength Steel
    These Grade 5 or Class 04 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.
    Steel—Best for dry environments since moisture will cause these nuts to rust.
    Thread
    Size
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    Steel
    M39 × 3 mm6019.5ISO Class 04
    		DIN 439B, ISO 40351000000000000000
     

    Nylon-Insert Locknuts

    Versatile yet economical, these are the most commonly used locknuts. The nylon insert grips the screw to prevent loosening from moderate vibration without damaging threads. However, the insert may become brittle if exposed to high temperatures. These locknuts are reusable a handful of times, but the holding power decreases with each use.
    High-Strength Steel
    Image of Product. Front orientation. Locknuts. Nylon-Insert Locknuts.
    Rated Grade 8, Grade C, or Class 10, these locknuts are about 25% stronger than medium-strength steel nuts. 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
    Insert Max.
    Temp., ° F
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M39 × 4 mm6039ISO Class 10
    		220DIN 9851000000000000000
     
    Medium-Strength Steel
    Image of Product. Front orientation. Locknuts. Nylon-Insert Locknuts.
    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
    Insert Max.
    Temp., ° F
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M39 × 3 mm6039ISO Class 8
    		220DIN 985, ISO 105111000000000000000
     
    back to top