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    61 Products

    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.
    Black-Corrosion-Resistant-Coated Steel—These nuts combine a finished appearance with the rust resistance of stainless steel. The coating has been tested to extreme standards, including 1,000 hours of salt spray resistance, to hold up in wet and outdoor environments. Also known as black luster.
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Insert Max.
    Temp., ° F
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1 mm138ISO Class 10
    220DIN 985, ISO 1051110000000000000000
    M8 × 1.25 mm138ISO Class 10
    220DIN 9855000000000000000
     
    Black-Corrosion-Resistant-Coated Steel
    M8 × 1.25 mm138ISO Class 10
    220DIN 985500000000000000
     
    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-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.
    Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.
    Black-Corrosion-Resistant-Coated Steel—These nuts combine a finished appearance with the rust resistance of stainless steel. The coating has been tested to extreme standards, including 1,000 hours of salt spray resistance, to hold up in wet and outdoor environments. Also known as black luster.
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Insert Max.
    Temp., ° F
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Yellow-Chromate-Plated Steel
    M8 × 1.25 mm138ISO Class 8
    220DIN 985, ISO 10511100000000000000000
     
    Zinc-Plated Steel
    M8 × 1 mm138ISO Class 8
    220DIN 985, ISO 10511250000000000000
    M8 × 1.25 mm138ISO Class 8
    220DIN 985, ISO 1051110000000000000000
     
    Black-Corrosion-Resistant-Coated Steel
    M8 × 1.25 mm138ISO Class 8
    220DIN 985, ISO 10511500000000000000
     
    Low-Strength Steel
    Image of Product. Front orientation. Locknuts. Nylon-Insert Locknuts.
    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.,
    mm
    Ht.,
    mm
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm13822010000000000000000
     
    Corrosion-Resistant Stainless Steel
    Image of Product. Front orientation. Locknuts. Nylon-Insert Locknuts.
    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.
    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.
    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.,
    mm
    Ht.,
    mm
    Insert Max.
    Temp., ° F
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    M8 × 1 mm138220DIN 9855000000000000000
    M8 × 1.25 mm138220DIN 985500000000000000
     
    Black-Oxide 18-8 Stainless Steel
    M8 × 1.25 mm138240DIN 985100000000000000
     
    316 Stainless Steel
    M8 × 1.25 mm138220DIN 985250000000000000
     

    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.
    Low-Strength Steel
    Image of Product. Front orientation. Locknuts. Thin-Profile Nylon-Insert Locknuts.
    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.,
    mm
    Ht.,
    mm
    Insert Max.
    Temp., ° F
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm136.8245ISO 10511500000000000000
     

    High-Profile Nylon-Insert Locknuts

    Slightly taller than standard-profile locknuts, these have a larger gripping area so your wrench or socket won't slip off as you tighten them. They're often used in vehicles and machinery where fasteners can be difficult to reach. 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. High-Profile 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
    M8 × 1.25 mm139.5ISO Class 10
    220DIN 9822500000000000000
     
    Medium-Strength Steel
    Image of Product. Front orientation. Locknuts. High-Profile 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-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.
    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-Yellow-Chromate-Plated Steel
    M8 × 1.25 mm139.5ISO Class 8
    220DIN 982, ISO 7040100000000000000000
     
    Zinc-Plated Steel
    M8 × 1.25 mm139.5ISO Class 8
    220DIN 982, ISO 70405000000000000000
     
    Corrosion-Resistant Stainless Steel
    Image of Product. Front orientation. Locknuts. High-Profile Nylon-Insert Locknuts.
    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.,
    mm
    Ht.,
    mm
    Insert Max.
    Temp., ° F
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    M8 × 1.25 mm139.5220DIN 9821000000000000000
     
    316 Stainless Steel
    M8 × 1.25 mm139.5220DIN 982100000000000000
     

    Top-Lock Distorted-Thread Locknuts

    Irregularly shaped threads at the top of these locknuts grip the screw for a stronger hold than nylon-insert locknuts. Although the threads prevent the nut from backing out due to vibration, they also increase the effort to install and remove. To get these nuts off, you may need special tools, such as an impact wrench or propane torch. Nuts are not reusable.
    High-Strength Steel
    Image of Product. Front orientation. Locknuts. Top-Lock Distorted-Thread 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-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.
    Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.
    Black-Phosphate-Coated Steel—The dark coating creates both a finished appearance and a barrier against rust that's comparable to zinc yellow-chromate plating.
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Pkg.
    Qty.
    Pkg.
    Zinc-Yellow-Chromate-Plated Steel
    M8 × 1 mm138ISO Class 10
    1000000000000000
    M8 × 1.25 mm138ISO Class 10
    5000000000000000
     
    Zinc-Plated Steel
    M8 × 1 mm138ISO Class 10
    5000000000000000
    M8 × 1.25 mm138ISO Class 10
    500000000000000
     
    Black-Phosphate-Coated Steel
    M8 × 1 mm138ISO Class 10
    100000000000000
    M8 × 1.25 mm138ISO Class 10
    2500000000000000
     
    Medium-Strength Steel
    Image of Product. Front orientation. Locknuts. Top-Lock Distorted-Thread 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
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm138ISO Class 8
    DIN 980V5000000000000000
     
    Corrosion-Resistant Stainless Steel
    Image of Product. Front orientation. Locknuts. Top-Lock Distorted-Thread Locknuts.
    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.
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    M8 × 1 mm136.4DIN 980, ISO 70425000000000000000
    M8 × 1.25 mm136.4DIN 980, ISO 70421000000000000000
     

    Center-Lock Distorted-Thread Locknuts

    Also known as reversible locknuts, these thread on from either side, so you don't have to worry about fastening them incorrectly and damaging your screw. The irregularly shaped threads in the middle grip the screw for a stronger hold than nylon-insert locknuts. Although the threads prevent the nut from backing out due to vibration, they also increase the effort to install and remove. To get these nuts off, you may need special tools, such as an impact wrench or propane torch. Nuts are not reusable.
    Medium-Strength Steel
    Image of Product. Front orientation. Locknuts. Center-Lock Distorted-Thread 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
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1 mm136.5ISO Class 8
    10000000000000000
    M8 × 1.25 mm136.5ISO Class 8
    1000000000000000
     

    Locknuts with External-Tooth Lock Washer

    To save on assembly time, these locknuts combine a hex nut with a free-spinning lock washer, so you can twist them into place by hand. Once the nut is against your material surface, tighten it down with a wrench or socket to get the teeth to bite. Although these nuts install more quickly than nylon-insert locknuts, they don't hold up as well against vibration and can mar your material. As long as the washer stays intact, you can reuse them. Also known as Keps and K-lock nuts.
    Medium-Strength Steel
    Image of Product. Front orientation. ZoomedIn view. Locknuts. Locknuts with External-Tooth Lock Washer.
    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-Zinc-Plated Steel—The dark zinc plating withstands occasional exposure to moisture while creating a finished look.
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Washer
    OD, mm
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm138.5ISO Class 8
    15.52500000000000000
     
    Black-Zinc-Plated Steel
    M8 × 1.25 mm138.5ISO Class 8
    15.52500000000000000
     
    Corrosion-Resistant Stainless Steel
    Image of Product. Front orientation. ZoomedIn view. Locknuts. Locknuts with External-Tooth Lock Washer.
    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.
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Washer
    OD, mm
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    M8 × 1.25 mm138.515.1500000000000000
     

    Locknuts with Spring-Lock Washer

    The curved, spring-like washer grips surfaces more tightly than tooth-lock washers for better vibration resistance. These locknuts also install just as quickly since you can twist them into place by hand. Once the nut is against your material, tighten it down with a wrench or socket. The washer's smooth edges won't mar the surface like teeth can. As long as the washer stays intact, you can reuse these locknuts.
    Medium-Strength Steel
    Image of Product. Front orientation. Locknuts. Locknuts with Spring-Lock Washer.
    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
    Washer
    OD, mm
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm138.8ISO Class 8
    1850000000000000000
     

    Locknuts for use with Cotter Pins

    Use these locknuts to secure rotating parts subjected to mild vibration, such as the wheels on carts and hand trucks. They’re not recommended for use on parts exposed to high vibration because the pin can shear under prolonged stress. These nuts are reusable, but you'll need a new cotter pin (not included) with each use.
    Medium-Strength Steel
    Image of ProductInUse. Front orientation. Locknuts. Locknuts for use with Cotter Pins.
    Image of Product. Front orientation. Locknuts. Locknuts for use with Cotter Pins.
    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
    For Cotter
    Pin Dia., mm
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm139.5ISO Class 8
    2DIN 935500000000000000
     

    Flex-Top Locknuts for Heavy Vibration

    The top section of these nuts expands to grip the screw on all sides for a stronger hold than both nylon-insert and distorted-thread locknuts. They’re often used 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
    Image of Product. Front orientation. Locknuts. Flex-Top Locknuts for Heavy Vibration.
    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.
    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.
    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.,
    mm
    Ht.,
    mm
    Pkg.
    Qty.
    Pkg.
    Black-Oxide Steel
    M8 × 1.25 mm1310.4100000000000000
     
    Cadmium-Plated Steel
    M8 × 1.25 mm1310.410000000000000
     
    Corrosion-Resistant Stainless Steel
    Image of Product. Front orientation. Locknuts. Flex-Top Locknuts for Heavy Vibration.
    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.,
    mm
    Ht.,
    mm
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    M8 × 1.25 mm1310.4100000000000000
     
    316 Stainless Steel
    M8 × 1.25 mm1310.4100000000000000
     

    Spring-Stop Locknuts

    These locknuts withstand heavy vibration similar to distorted-thread nuts, and you can use them over and over. The prongs at the top bend when tightened to create tension for a secure hold. As you remove the locknut, the prongs spring back to their original shape, so you can install the nut again without losing holding power. Also known as Fuji locknuts.
    Low-Strength Steel
    Image of Product. Front orientation. Locknuts. Spring-Stop Locknuts.
    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.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm127.3ISO Class 6
    10000000000000000
     
    Corrosion-Resistant Stainless Steel
    Image of Product. Front orientation. Locknuts. Spring-Stop Locknuts.
    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.
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    M8 × 1.25 mm137.25000000000000000
     

    Serrated Flange Nuts

    Serrations bite into material for mild vibration resistance while the flange eliminates the need for a separate washer. These nuts are ideal for securing screws in oversized or irregularly shaped holes since the flange covers a larger area than standard nuts. You can use them again and again without sacrificing strength. However, the serrations may mar the surface of your material. Also known as collar nuts.
    Medium-Strength Steel
    Image of Product. Bottom orientation. Flange Nuts. Serrated Flange Nuts.
    Rated Grade 5, Grade F, or Class 8, these 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.
    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.
    Black-Oxide Steel—Typically chosen for their appearance, these nuts have a dark, matte coating that creates 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.
    Flange,
    mm
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Dia.
    Thk.
    Fastener Strength
    Grade/Class
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1 mm13817.91.2ISO Class 8
    DIN 6923100000000000000000
    M8 × 1.25 mm13817.91.2ISO Class 8
    DIN 6923, ISO 416110000000000000000
     
    Zinc-Yellow-Chromate-Plated Steel
    M8 × 1.25 mm13817.91.2ISO Class 8
    DIN 6923, ISO 41615000000000000000
     
    Black-Oxide Steel
    M8 × 1 mm13817.91.2ISO Class 8
    DIN 692310000000000000000
    M8 × 1.25 mm13817.91.2ISO Class 8
    DIN 692310000000000000000
     
    Steel
    M8 × 1 mm13817.91.2ISO Class 8
    DIN 692310000000000000000
    M8 × 1.25 mm13718.252.6ISO Class 8
    2500000000000000
     
    High-Strength Steel
    Image of Product. Bottom orientation. Flange Nuts. Serrated Flange Nuts.
    Rated Grade 8, Grade G, or Class 10, these are about 25% stronger than medium-strength steel nuts. They are commonly used to fasten components in valves, pumps, and motors. 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.
    Flange,
    mm
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Dia.
    Thk.
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm13817.91.2ISO Class 10
    DIN 692350000000000000000
     
    Steel
    M8 × 1.25 mm13817.91.2ISO Class 10
    DIN 69235000000000000000
     
    Corrosion-Resistant Stainless Steel
    Image of Product. Bottom orientation. Flange Nuts. Serrated Flange 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.
    Super-Corrosion-Resistant 316 Stainless Steel—Our most corrosion-resistant flange nuts, these hold up in just about any environment, including harsh weather, salt water, and most chemicals.
    Flange,
    mm
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Dia.
    Thk.
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    M8 × 1.25 mm13817.91.3DIN 69232500000000000000
     
    Super-Corrosion-Resistant 316 Stainless Steel
    M8 × 1.25 mm13817.91.3DIN 6923100000000000000
     

    Nylon-Insert Flange Nuts

    A nylon insert grips the screw for a stronger hold than a serrated flange, without damaging threads or marring the surface of your material. However, the insert may become brittle if exposed to high temperatures. These nuts have a flange that distributes pressure evenly across the mounting surface, so you don't need a separate washer. They are ideal for securing screws in oversized or irregularly shaped holes since the flange covers a larger area than standard nuts. You can reuse them a handful of times, but their holding power will decrease with each use. Also known as collar nuts.
    Medium-Strength Steel
    Image of Product. Front orientation. Flange Nuts. Nylon-Insert Flange Nuts.
    Rated Grade 5, Grade F, or Class 8, these 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 Corrosion-Resistant-Coated Steel—Combines a finished appearance with the rust resistance of stainless steel. The coating has been tested to extreme standards, including 1,000 hours of salt spray resistance, to hold up in wet and outdoor environments. Also known as black luster.
    Flange,
    mm
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Dia.
    Thk.
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm1311.117.91.2ISO Class 8
    DIN 6926250100000000000000000
     
    Black Corrosion-Resistant-Coated Steel
    M8 × 1.25 mm1311.117.91.2ISO Class 8
    DIN 692625050000000000000
     
    High-Strength Steel
    Image of Product. Front orientation. Flange Nuts. Nylon-Insert Flange Nuts.
    Rated Grade 8, Grade G, or Class 10, these are about 25% stronger than medium-strength steel nuts. They are commonly used to fasten components in valves, pumps, and motors. 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.
    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.
    Flange,
    mm
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Dia.
    Thk.
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm1311.117.91.2ISO Class 10
    DIN 69262501000000000000000
     
    Zinc-Yellow-Chromate-Plated Steel
    M8 × 1.25 mm131117.91.2ISO Class 10
    DIN 69262505000000000000000
     
    Corrosion-Resistant Stainless Steel
    Image of Product. Front orientation. Flange Nuts. Nylon-Insert Flange 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.
    Flange,
    mm
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Dia.
    Thk.
    Specs.
    Met
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    M8 × 1.25 mm1311.117.91.2DIN 69262505000000000000000
     

    Distorted-Thread Flange Nuts

    The strongest hold of all the flange nuts we offer, these have irregularly shaped threads that grip the screw to resist loosening. The threads prevent the nut from backing out due to high vibration, but they also increase the effort to install and remove. To get these nuts off, you may need special tools, such as an impact wrench or propane torch, so they are not reusable. Nuts have a flange that distributes pressure evenly across the mounting surface without the need for a separate washer. They are ideal for securing screws in oversized or irregularly shaped holes since the flange covers a larger area than standard nuts. Also known as collar nuts.
    Medium-Strength Steel
    Image of Product. Bottom orientation. Flange Nuts. Distorted-Thread Flange Nuts.
    Rated Grade 5, Grade F, or Class 8, these 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.
    Flange,
    mm
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Dia.
    Thk.
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm139.417.91.2ISO Class 8
    DIN 692750000000000000000
     
    High-Strength Steel
    Image of Product. Bottom orientation. Flange Nuts. Distorted-Thread Flange Nuts.
    Rated Grade 8, Grade G, or Class 10, these are about 25% stronger than medium-strength steel nuts. They are commonly used to fasten components in valves, pumps, and motors. 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 that creates a finished look. They offer minimal corrosion resistance, so they're best for dry environments.
    Flange,
    mm
    Thread Size
    Wd.,
    mm
    Ht.,
    mm
    Dia.
    Thk.
    Fastener Strength
    Grade/Class
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm139.417.91.2ISO Class 10
    DIN 6927, EN 1664, ISO 7044250000000000000
     
    Black-Oxide Steel
    M8 × 1.25 mm139.417.91.2ISO Class 10
    DIN 6927, EN 1664, ISO 70441000000000000
     

    Nylon-Insert Cap Nuts

    Get the protection of a cap nut with the vibration resistance of a locknut. These nuts not only conceal protruding screw threads, they also have a nylon insert that grips the screw to prevent loosening from moderate vibration. However, the insert may become brittle if exposed to high temperatures. Nuts are reusable a handful of times, but their holding power decreases with each use.
    Low-Strength Steel
    Image of Product. Bottom orientation. Cap Nuts. Nylon-Insert Cap Nuts.
    Rated Grade 2, Class 6, or lower, these nuts 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
    Thread
    Dp., mm
    Wd.,
    mm
    Ht.,
    mm
    Fastener Strength
    Grade/Class
    Specs.
    Met
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    Zinc-Plated Steel
    M8 × 1.25 mm5.21314ISO Class 6
    DIN 98624525000000000000000
     

    Cap Nuts with Threadlocker

    These nuts not only conceal and protect protruding screw threads, they also resist loosening from mild vibration. They have a nylon patch bonded to their threads that grips screws for a tighter hold than standard cap nuts. They’re reusable a handful of times, but the patch’s holding power decreases with each use. Also known as acorn nuts, they have a smooth, rounded head that creates a finished look.
    Stainless Steel
    Image of Product. Front orientation. Contains Annotated, Border. Cap Nuts. Cap Nuts with Threadlocker.
    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
    Thread
    Dp., mm
    Wd.,
    mm
    Ht.,
    mm
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    M8 × 1.25 mm8.21315DIN 15875000000000000000
     
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