McMaster-Carr logo
    Filter by
    System of Measurement
    Hex Nut Profile
    Industrial Info Compare
    Thread Direction
    Industrial Info Compare
    Thread Spacing
    Industrial Info Snippet
    Thread Type
    Fastener Strength Rating
    DFARS Specialty Metals
    Industrial Info Compare
    Export Control Classification Number (ECCN)
    Industrial Info Snippet
    Drive Style
    Industrial Info Snippet
    Military Specification
    Insert Maximum Temperature
    Head Diameter
    Attribute Image
    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)
    26 Products
    About Hex Nuts
    industrial info icon

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

    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.
    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
    7/16"-14
    		11/16"1/4"SAE Grade 5
    		ASME B18.2.25000000000000000
     
    Steel
    7/16"-14
    		11/16"1/4"SAE Grade 5
    		ASME B18.2.2500000000000000
     
    High-Strength Steel
    Rated Grade 8, Grade C, or Class 10, these nuts are about 25% stronger than medium-strength steel nuts. They are commonly used to fasten components in valves, pumps, motors, and other high-stress applications. 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
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Yellow-Chromate-Plated Steel
    7/16"-14
    		11/16"1/4"SAE Grade 8
    		ASME B18.2.225000000000000000
     
    Steel
    7/16"-14
    		11/16"1/4"SAE Grade 8
    		ASME B18.2.22500000000000000
     
    Low-Strength Steel
    Rated Grade 2, Class 6, or lower, these nuts are about half as strong as medium-strength nuts. They are suitable for light duty fastening applications, such as securing access panels. Use them with screws that have a similar 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.
    Thread
    Size
    Wd.
    Ht.
    Fastener Strength
    Grade/Class
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    7/16"-14
    		11/16"1/4"SAE Grade 2
    		100000000000000000
     
    Steel
    7/16"-14
    		11/16"1/4"SAE Grade 2
    		1000000000000000
     
    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.
    Ht.
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    7/16"-14
    		11/16"1/4"50000000000000000
     
    Highly-Corrosion-Resistant 316 Stainless Steel
    7/16"-14
    		11/16"1/4"100000000000000
     
    Brass
    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.
    Ht.
    Pkg.
    Qty.
    Pkg.
    Brass
    7/16"-14
    		11/16"1/4"1000000000000000
     

    Left-Hand-Thread Hex Nuts

    Image of Product. Front orientation. Contains Annotated, MultipleImages. Hex Nuts. Left-Hand-Thread 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.
    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.
    Pkg.
    Qty.
    Pkg.
    Highly-Corrosion-Resistant 316 Stainless Steel
    7/16"-14
    		11/16"3/8"1000000000000000
     

    Thin-Profile Nylon-Insert Locknuts

    Image of Product. Front orientation. Locknuts. Thin-Profile Nylon-Insert Locknuts.
    About half the height of standard-profile locknuts, these fit in spaces with low clearance. You can also use them as jam nuts by threading them against a hex nut to hold it in place. 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.
    Thread
    Size
    Wd.
    Ht.
    Fastener Strength
    Grade/Class
    Insert Max.
    Temp.
    Pkg.
    Qty.
    Pkg.
    Zinc-Yellow-Chromate-Plated Steel
    7/16"-14
    		5/8"5/16"SAE Grade 8
    		Not Rated2500000000000000
     
    Low-Strength Steel
    Rated Grade 2, Class 6, or lower, these locknuts are about half as strong as medium-strength steel nuts. Use them with screws that have a similar 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.
    Thread
    Size
    Wd.
    Ht.
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    7/16"-14
    		5/8"5/16"22010000000000000000
     
    Corrosion-Resistant Stainless Steel
    18-8 Stainless Steel—The choice for wet and outdoor environments, these locknuts resist rust. However, they won't hold up to the harsh chemicals that 316 stainless steel can.
    316 Stainless Steel—Our most corrosion-resistant nuts, these hold up in just about any environment. They won't degrade from exposure to weather, salt water, and most chemicals.
    Thread
    Size
    Wd.
    Ht.
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    7/16"-14
    		5/8"5/16"2201000000000000000
     
    316 Stainless Steel
    7/16"-14
    		5/8"5/16"2202500000000000000
     

    Thin-Heavy-Profile Hex Nuts

    Image of Product. Front orientation. Hex Nuts. Thin-Heavy-Profile Hex Nuts.
    About half the height of standard-profile hex nuts and 10% wider, these fit in spaces with low clearance and handle heavier loads by distributing them over a larger area. You can also use them as jam nuts by threading them against another hex nut to hold it in place.
    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.
    Ht.
    Fastener Strength
    Grade/Class
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    Steel
    7/16"-14
    		3/4"17/64"ASTM Grade 2H
    		ASME B18.2.2, ASTM A194100000000000000
     
    Low-Strength Steel
    Rated Grade 2, Class 6, or lower, these nuts are about half as strong as medium-strength nuts. They are suitable for light duty fastening applications, such as securing access panels. Use them with screws that have a similar strength rating to avoid stripping threads during installation.
    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.
    Ht.
    Fastener Strength
    Grade/Class
    Pkg.
    Qty.
    Pkg.
    Black-Oxide Steel
    7/16"-14
    		3/4"17/64"—25000000000000000
     
    Steel
    7/16"-14
    		3/4"17/64"SAE Grade 2
    		500000000000000
     
    Brass
    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.
    Ht.
    Pkg.
    Qty.
    Pkg.
    Brass
    7/16"-14
    		3/4"17/64"1000000000000000
     

    Left-Hand-Thread Thin-Profile Hex Nuts

    Image of Product. Front orientation. Contains Annotated, MultipleImages. Hex Nuts. 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
    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.
    Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.
    Thread
    Size
    Wd.
    Ht.
    Fastener Strength
    Grade/Class
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    7/16"-14
    		11/16"1/4"SAE Grade 5
    		50000000000000000
     
    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.
    Thread
    Size
    Wd.
    Ht.
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    7/16"-14
    		11/16"1/4"ASME B18.2.2100000000000000
     

    Mil. Spec. Thin-Profile Hex Nuts

    Image of Product. Front orientation. Hex Nuts. Mil. Spec. Thin-Profile Hex Nuts.
    These nuts are manufactured and tested to strict U.S. military standards for material and construction. About half the height of standard-profile nuts, they 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.
    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.
    Thread
    Size
    Wd.
    Ht.
    Mil.
    Spec.
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    7/16"-14
    		11/16"1/4"MS35691-27Fed. Spec. FF-N-836
    		100000000000000
     

    Flanged Knurled-Head Thumb Nuts

    Image of Attribute. Front orientation. Contains Annotated. Thumb Nuts. Flanged Knurled-Head Thumb Nuts.
    The slip-resistant head is easy to grip, while the flange distributes pressure evenly across the mounting surface without the need for a separate washer. These nuts are often used to secure screws in oversized or irregularly shaped holes since the flange covers a larger area than standard nuts.
    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.
    Passivated 18-8 Stainless Steel—With an added layer of protection, these nuts stand up to strong acids and other harsh chemicals.
    Collar
    Thread
    Size
    Dia.
    Ht.
    Head
    Dia.
    Ht.
    Threading
    Each
    18-8 Stainless Steel
    7/16"-14
    		11/16"5/16"1"17/32"Fully Threaded00000000000000
     
    Passivated 18-8 Stainless Steel
    7/16"-14
    		11/16"5/16"1"17/32"Fully Threaded0000000000000
     

    Knurled-Head Thumb Nuts

    Image of Attribute. Front orientation. Contains Annotated. Thumb Nuts. Knurled-Head Thumb Nuts.
    Get a good grip on these nuts, even with oily fingers. They have a raised, slip-resistant head, so you can tighten them by hand and make controlled adjustments. Knurled-head nuts have a smaller profile than wing nuts, so they fit in tighter spots.
    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.
    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.
    Collar
    Thread
    Size
    Dia.
    Ht.
    Head
    Dia.
    Ht.
    Threading
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    7/16"-14
    		5/8"3/4"1 1/8"15/16"Fully Threaded1000000000000000
     
    Black-Oxide 18-8 Stainless Steel
    7/16"-14
    		5/8"3/4"1 1/8"15/16"Fully Threaded100000000000000
     

    Thin-Heavy-Profile Flex-Top Locknuts for Heavy Vibration

    Image of Product. Front orientation. Locknuts. Thin-Heavy-Profile Flex-Top Locknuts for Heavy Vibration.
    About two-thirds the height of standard flex-top nuts and 10% wider, these fit in spaces with low clearance and handle heavier loads by distributing them over a larger area. Because of the thin profile, you can also use them as jam nuts by threading them against a hex nut to hold it in place. The top section expands to grip the screw on all sides for a stronger hold than both nylon-insert and distorted-thread locknuts. As a result, they're suitable for use in equipment with constant, vigorous vibration, such as engines. These locknuts are reusable a handful of times, but the holding power decreases with each use.
    Steel
    These locknuts have equivalent strength to Grade 8 and Class 10 steel nuts. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.
    Cadmium-Plated Steel—These locknuts have good lubricity to thread on smoothly and ease installation. The plating also creates a barrier against rust that's comparable to zinc-yellow-chromate plating.
    Thread
    Size
    Wd.
    Ht.
    Pkg.
    Qty.
    Pkg.
    Cadmium-Plated Steel
    7/16"-14
    		3/4"21/64"100000000000000
     
    back to top