McMaster-Carr logo
    Filter by
    System of Measurement
    Thread Size
    Industrial Info Compare
    Nut Type
    Industrial Info Compare
    Hex Nut Profile
    Industrial Info Compare
    Thread Type
    Industrial Info Compare
    Specifications Met
    Thread Spacing
    Industrial Info Snippet
    DFARS Specialty Metals
    Industrial Info Compare
    Thread Direction
    Tensile Strength
    Industrial Info Snippet
    Locking Type
    Fastener Strength Rating
    Drive Style
    Industrial Info Snippet
    U.S.–Mexico–Canada Agreement (USMCA) Qualifying
    Export Control Classification Number (ECCN)
    Industrial Info Snippet
    Color
    Sold As
    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)
    13 Products
    About Hex Nuts
    industrial info icon

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

    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.
    Hot-Dipped Galvanized Steel—Combines the strength of steel with the rust resistance of stainless steel. These nuts are an economical alternative to 18-8 stainless steel in wet and outdoor environments, but they won't hold up to salt water and chemicals. The galvanized finish is thicker than other types of coatings, so the threads may be more likely to stick during installation. Use with other hot-dipped galvanized fasteners.
    Steel—Best for dry environments since moisture will cause these nuts to rust.
    PTFE-Coated Steel—A slippery PTFE coating prevents these nuts from becoming stuck during installation. They resist rust in wet and outdoor environments, however they're not recommended for prolonged exposure since the coating can wear off.
    Thread
    Size
    Wd.
    Ht.
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Hot-Dipped Galvanized Steel
    1 1/4"-8
    		2"1 7/32"ASTM Grade 2H
    		ASTM A194
    		195025A43600000
     
    Steel
    1 1/4"-8
    		2"1 7/32"ASTM Grade 2H
    		ASTM A194
    		190521A2750000
     
    Blue PTFE-Coated Steel
    1 1/4"-8
    		2"1 7/32"ASTM Grade 2H
    		ASTM A194
    		190212A81100000
     

    Heavy-Profile Hex Nuts for High-Pressure Applications

    Image of Product. Bottom orientation. Hex Nuts. Heavy-Profile Hex Nuts for High-Pressure Applications.
    These nuts are hardened, so they maintain their strength under high pressure and temperature. Pair them with ASTM A193 screws to fasten critical components, such as valves and flanges, in pressure tanks, boilers, and heat exchangers. About 10% wider and taller than standard-profile hex nuts, these handle heavier loads by distributing them over a larger area.
    High-Strength Steel
    Rated Grade 7 or Grade 8, these nuts 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.
    Steel—Best for dry environments since moisture will cause these nuts to rust.
    Thread
    Size
    Wd.
    Ht.
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    1 1/4"-8
    		2"1 7/32"ASTM Grade 7
    		ASTM A194
    		194485A24000000
     
    Steel
    1 1/4"-8
    		2"1 7/32"ASTM Grade 7
    		ASTM A194
    		194485A1120000
     
    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.
    Ht.
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Highly Corrosion-Resistant 316 Stainless Steel
    1 1/4"-8
    		2"1 1/4"ASTM Grade 8M
    		ASTM A194
    		197619A940000000
     

    Nylon-Insert Locknuts

    Image of Product. Front orientation. Locknuts. 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
    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-Yellow-Chromate-Plated Steel—With a more durable finish than clear zinc plating, these nuts are suitable for most wet and outdoor environments. However, they won't hold up to the harsh chemicals that stainless steel can.
    Steel—Best for dry environments since moisture will cause these nuts to rust.
    Thread
    Size
    Wd.
    Ht.
    Fastener Strength
    Grade/Class
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    Zinc-Yellow-Chromate-Plated Steel
    1 1/4"-8
    		2 1/64"1 41/64"SAE Grade 8
    		220197135A404000000
     
    Steel
    1 1/4"-8
    		2 1/64"1 41/64"SAE Grade 8
    		220190630A21100000
     

    Helical Threaded Inserts

    Image of Product. Pronged. Bottom orientation. Threaded Inserts. Helical Threaded Inserts, Pronged.

    Pronged

    Restore, reinforce, or create threads in metal. The tough coils on these inserts expand once installed to anchor in a tapped hole. Also known as Heli-Coil inserts, they're often used in engine heads and machinery housings where strong connections are critical. Unlike threadlocking inserts, you can remove and reuse them without them losing their strength.
    Installation requires a drill bit, a helical insert tap, and an installation tool.
    Pronged—The prong attaches to an installation tool for precise control as you drive inserts in. Remove the prong with a punch or break-off tool before inserting a screw.
    18-8 Stainless Steel—The choice for wet and outdoor environments, these inserts resist rust and mild chemicals.
    Inserts
    Through-Hole
    Taps
    Closed-End
    Hole Taps
    Installation
    Tools
    Thread
    Size
    Installed
    Lg.
    Drill Bit
    Size
    For Max.
    Hole Dia.
    Pkg.
    Qty.
    Pkg.
    Each
    Each
    Each
    Pronged
     
    18-8 Stainless Steel
    1 1/4"-8
    		1.875"1 1/4"
    		1.250"192335A1110000092335A311000000091709A310000000092335A511000000
     
    Extraction Tools
    Remove installed helical inserts.
    For Pronged Helical Inserts—Place the tip into pronged inserts and lightly strike the tool’s head. Then, turn the tool counterclockwise with pressure to extract the insert.
    For Thread Size
    Each
    For Pronged Helical Inserts
    1 1/8"-7, 1 1/8"-12, 1 1/4"-7, 1 1/4"-8, 1 1/4"-12, 1 3/8"-6, 1 3/8"-12, 1 1/2"-6, 1 1/2"-8, 1 1/2"-12, M27, M30, M36, M39
    		90254A3600000000
     
    back to top