McMaster-Carr logo
    Filter by
    System of Measurement
    Thread Size
    Industrial Info Compare
    Hex Nut Profile
    Industrial Info Compare
    Thread Spacing
    Industrial Info Compare
    Thread Type
    Thread Direction
    Industrial Info Compare
    Drive Style
    Industrial Info Snippet
    Fastener Strength Rating
    U.S.–Mexico–Canada Agreement (USMCA) Qualifying
    Export Control Classification Number (ECCN)
    Industrial Info Snippet
    DFARS Specialty Metals
    Industrial Info Compare
    Length
    Attribute Image
    Locking Type
    Enter e-mail addresses in the fields below
    Message
    Cancel
    Comments
    E-mail address (if you would like a response)
    32 Products
    About Hex Nuts
    industrial info icon

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

    Hex Nuts

    The most commonly used hex nuts, these are suitable for fastening most machinery and equipment.
    Medium-Strength Steel
    Image of Product. Front orientation. Hex Nuts. Hex Nuts.
    Image of Specification. Front orientation. Hex Nuts. 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.
    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
    M33 × 3.5 mm5026Class 8DIN 934190591A14700000
     
    Black-Oxide Steel
    M33 × 3.5 mm5026Class 8DIN 934190593A01800000
     
    Steel
    M33 × 2 mm5026Class 8DIN 934191423A34000000
    M33 × 3 mm5026Class 8DIN 934191423A33000000
    M33 × 3.5 mm5026Class 8DIN 934190592A3410000
     
    Extreme-Strength Steel
    Image of Product. Front orientation. Hex Nuts. Hex Nuts.
    Image of Specification. Front orientation. Hex Nuts. Hex Nuts.
    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
    M33 × 3.5 mm5026Class 12DIN 934194223A112000000
     
    Corrosion-Resistant Stainless Steel
    Image of Product. Front orientation. Hex Nuts. Hex Nuts.
    Image of Specification. Front orientation. Hex Nuts. Hex 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.
    Black-Oxide 18-8 Stainless Steel—Typically chosen for their appearance, these nuts have a dark, matte coating to create a finished look. They resist rust in wet and outdoor environments, but won't hold up to the harsh chemicals that 316 stainless steel can.
    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.
    18-8 Stainless Steel
    M33 × 1.5 mm5024.7DIN 934193850A141000000
    M33 × 3.5 mm5024.7DIN 934191828A11200000
     
    Black-Oxide 18-8 Stainless Steel
    M33 × 1.5 mm5026DIN 934193850A13200000
    M33 × 3.5 mm5026DIN 934198676A11900000
     
    Highly Corrosion-Resistant 316 Stainless Steel
    M33 × 3.5 mm5026DIN 934194150A11700000
     
    Brass
    Image of Product. Front orientation. Hex Nuts. Hex Nuts.
    Image of Specification. Front orientation. Hex Nuts. Hex Nuts.
    Brass—Conductive and nonmagnetic, brass nuts are commonly used to secure electrical equipment, such as circuit board assemblies and mounting brackets, inside enclosures. They're also softer than most metals, so they won't damage other fastening components.
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Brass
    M33 × 3.5 mm5026DIN 934190690A118000000
     

    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
    M33 × 1.5 mm5014DIN 936190364A119000000
    M33 × 2 mm5014DIN 936190364A1180000
    M33 × 2 mm5016.5Class 04DIN 439B, ISO 4035190326A22300000
    M33 × 3.5 mm5014DIN 936190370A11400000
     
    Corrosion-Resistant 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.
    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.
    18-8 Stainless Steel
    M33 × 3.5 mm5014DIN 936190381A112000000
     
    Highly Corrosion-Resistant 316 Stainless Steel
    M33 × 2 mm5016.5DIN 439B, ISO 4035197289A13500000
     

    Shock Absorber Mounting Nuts

    Image of Product. Front orientation. Shock Absorber Mounting Nuts. Hex Nuts.

    Hex Nuts

    Steel
    Thread Size
    Each
    Hex Nuts
    M33 × 1.5 mm9530K84000000
     

    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
    M33 × 3.5 mm5033Class 10220DIN 985194645A340000000
     
    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
    M33 × 2 mm5033Class 8220DIN 985, ISO 10511190576A384000000
    M33 × 3.5 mm5033Class 8220DIN 985, ISO 10511190576A16300000
     

    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
    M33 × 3.5 mm5533ASTM Grade 2H
    ASTM A194, DIN 6915198498A116000000
     

    Coupling Nuts

    Image of Product. Front orientation. Coupling Nuts. Coupling Nuts.
    Also known as extension nuts, these are commonly used to connect lengths of threaded rod and join threaded parts.
    Material Certificate Icon
    Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.
    Corrosion-Resistant 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.
    Each
    Thread Size
    Lg.,
    mm
    Wd.,
    mm
    Threading
    Specs.
    Met
    1-9
    10-49
    50-Up
    18-8 Stainless Steel
    M33 × 3.5 mm9950Fully ThreadedDIN 633493590A3360000000000000000000
     

    Left-Hand-Thread Thin-Profile Hex Nuts

    These nuts tighten when turned to the left. Use them with left-hand rods and screws to prevent counterclockwise-moving parts from loosening. 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
    Image of Product. Front orientation. Contains Annotated, MultipleImages. Hex Nuts. Left-Hand-Thread Thin-Profile Hex Nuts.
    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.
    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.
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    Black-Oxide Steel
    M33 × 3.5 mm5016.5Class 04ASTM A108, DIN 439B, ISO 4035190519A827000000
     

    Key-Locking Threaded Inserts for Soft Metal

    Image of Product. Bottom orientation. Threaded Inserts. Key-Locking Threaded Inserts for Soft Metal.
    Add strong threads in soft metal, such as aluminum. The keys on these inserts drive into holes to hold more securely than thread-locking or helical inserts. They prevent slipping and rotating, so they’re stable enough for use in vehicle or aerospace parts that experience heavy vibration. These inserts are comparable to Keensert inserts.
    To install, drill and tap a hole in your material. Then, thread the insert onto the installation tool and screw it into the hole. Place the tool over the keys and hit it with a hammer to drive them in.
    Standard Wall—Stronger than thin-wall inserts, these are your go-to choice for threading most holes.
    Black Phosphate-Coated Steel—These inserts resist occasional moisture.
    18-8 Stainless Steel—The choice for wet and outdoor environments, these inserts resist rust and mild chemicals.
    Inserts
    Installation
    Tools
    Inserts with
    Installation Tools
    Each
    Thread
    Size
    For Tap Thread
    Size
    Installed
    Lg., mm
    Drill Bit
    Size, mm
    For Max.
    Hole Dia., mm
    No. of Locking
    Keys
    1-9
    10-Up
    Each
    No. of Inserts
    Included
    Each
    Standard Wall
     
    Black Phosphate-Coated Steel
    M24 x 2 mmM33 x 2 mm3331
    31490245A21700000000000094010A365000000———0
    M24 x 3 mmM33 x 2 mm3331
    31490245A213000000000094010A36500000290245A3410000000
     
    18-8 Stainless Steel
    M24 x 3 mmM33 x 2 mm3331
    31493715A685000000000094010A36500000———0
     

    Screw-Locking Seize-Resistant Key-Locking Threaded Inserts for Soft Metal

    Image of Product. Bottom orientation. Threaded Inserts. Screw-Locking Seize-Resistant Key-Locking Threaded Inserts for Soft Metal.
    Create the tightest hold in aluminum and other soft metal without screws sticking. The lubricant on these inserts eases installation, and the irregularly shaped threads won’t let screws back out from vibration. Inserts have keys that drive into material to prevent them from slipping or rotating in the hole.
    To install, drill and tap a hole in your material. Then, thread the insert onto the installation tool and screw it into the hole. Place the tool over the keys and hit it with a hammer to drive them in.
    Standard Wall—Stronger than thin-wall inserts, these are your go-to choice for threading most holes.
    Dry-Film-Lubricated Cadmium-Plated Steel—The plating creates a barrier against rust.
    Inserts
    Installation
    Tools
    Thread
    Size
    For Tap Thread
    Size
    Installed
    Lg., mm
    Drill Bit
    Size, mm
    For Max.
    Hole Dia., mm
    No. of Locking
    Keys
    Each
    Each
    Standard Wall
     
    Dry-Film-Lubricated Cadmium-Plated Steel
    M24 x 3 mmM33 x 2 mm3331
    31497255A338000000093904A798000000
     

    Key-Locking Threaded Inserts with Installation Tools

    Image of Product. Front orientation. Threaded Inserts. Key-Locking Threaded Inserts with Installation Tools.
    Paired with the right tool for installation, these inserts create strong threads in soft metal, such as aluminum. They have keys that drive into material to prevent inserts from slipping and rotating in the hole.
    Standard Wall—Stronger than thin-wall inserts, these are your go-to choice for threading most holes.
    Black Phosphate-Coated Steel—These inserts resist occasional moisture.
    Thread
    Size
    For Tap Thread
    Size
    Installed
    Lg., mm
    Drill Bit
    Size, mm
    For Max.
    Hole Dia., mm
    No. of Locking
    Keys
    No. of Inserts
    Included
    Each
    Standard Wall
     
    Black Phosphate-Coated Steel
    M24 x 3 mmM33 x 2 mm3331
    314290245A3410000000
     
    back to top