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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
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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.
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.
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.
Low-Strength Steel
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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. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Zinc-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 3/4" | 220 | 25 | 000000000 | 000000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Corrosion-Resistant Stainless Steel
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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.
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.
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.
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.
Thread Size | Wd. | Ht. | Fastener Strength Grade/Class | Insert Max. Temp., ° F | Pkg. Qty. | Pkg. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Zinc-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 25/64" | SAE Grade 5 | 220 | 5 | 000000000 | 000000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Low-Strength Steel
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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. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Zinc-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 25/64" | 220 | 50 | 000000000 | 000000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Corrosion-Resistant Stainless Steel
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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. | Ht. | Insert Max. Temp., ° F | Pkg. Qty. | Pkg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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18-8 Stainless Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 25/64" | 220 | 1 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mil. Spec. Nylon-Insert Locknuts
These locknuts are manufactured and tested to strict U.S. military standards for material and construction. 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
![]() |
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.
Cadmium Yellow-Chromate-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. | Mil. Spec. | Insert Max. Temp., ° F | Pkg. Qty. | Pkg. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Cadmium Yellow-Chromate-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 3/4" | MS21044-N10 | 250 | 1 | 000000000 | 00000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mil. Spec. Thin-Profile Nylon-Insert Locknuts
These locknuts are manufactured and tested to strict U.S. military standards for material and construction. They are about half the height of standard-profile locknuts to 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.
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.
Thread Size | Wd. | Ht. | Mil. Spec. | Insert Max. Temp., ° F | Specs. Met | Pkg. Qty. | Pkg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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18-8 Stainless Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 13/32" | MS21083C10 | 250 | NASM21083 | 1 | 000000000 | 000000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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
![]() |
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-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.
Zinc-Flake-Coated Steel—The most durable zinc coating, this multilayer finish resists wear for long-term rust protection. However, similar to zinc-yellow-chromate plating, it won't hold up to harsh chemicals like stainless steel can.
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.
Steel—Best for dry environments since moisture will cause these nuts to rust.
Thread Size | Wd. | Ht. | Fastener Strength Grade/Class | Pkg. Qty. | Pkg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Zinc-Yellow-Chromate-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | ASTM Grade C | 5 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zinc-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | ASTM Grade C | 25 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Black-Oxide Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | ASTM Grade C | 5 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zinc-Flake-Coated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | ASTM Grade C | 1 | 000000000 | 0000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Cadmium-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | ASTM Grade C | 25 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | ASTM Grade C | 25 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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.
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.
Thread Size | Wd. | Ht. | Pkg. Qty. | Pkg. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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18-8 Stainless Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | 1 | 000000000 | 00000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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.
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 | Pkg. Qty. | Pkg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Zinc-Yellow-Chromate-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | SAE Grade 8 | 5 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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. | Fastener Strength Grade/Class | Pkg. Qty. | Pkg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Zinc-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | SAE Grade 2 | 25 | 000000000 | 000000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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.
Thread Size | Wd. | Ht. | Pkg. Qty. | Pkg. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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18-8 Stainless Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | 5 | 000000000 | 000000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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
![]() | ![]() |
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. | Ht. | Fastener Strength Grade/Class | For Cotter Pin Dia. | Pkg. Qty. | Pkg. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Zinc-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | SAE Grade 5 | 5/32" | 10 | 000000000 | 000000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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. | For Cotter Pin Dia. | Pkg. Qty. | Pkg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Zinc-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 35/64" | 5/32" | 10 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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.
Thread Size | Wd. | Ht. | For Cotter Pin Dia. | Pkg. Qty. | Pkg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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18-8 Stainless Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 23/32" | 5/32" | 1 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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
![]() |
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.
Thin-Profile Flex-Top Locknuts for Heavy Vibration
About two-thirds the height of standard steel-insert locknuts, these fit in spaces with low clearance and offer the most secure hold of all our thin-profile locknuts. You can also use them as jam nuts by threading them against a hex nut to hold it in place. The tab on the insert stops the nut from rotating, even under extreme vibration. These locknuts are ideal for equipment with constant motion or jarring starts and stops, including conveyors, shakers, and compactors. In fact, they're so secure that they're even used to fasten components on roller coasters. These locknuts are also reusable, but their holding power decreases after the first use, so you should use a new nut for the strongest possible hold.
Steel
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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.
Steel—Best for dry environments since moisture will cause these nuts to rust.
Corrosion-Resistant Stainless Steel
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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. | Ht. | Pkg. Qty. | Pkg. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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18-8 Stainless Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 13/32" | 1 | 000000000 | 000000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mil. Spec. Flex-Top Locknuts for Heavy Vibration
These locknuts are manufactured and tested to strict U.S. military standards for material and construction. 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
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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 Yellow-Chromate-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. | Mil. Spec. | Pkg. Qty. | Pkg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Cadmium Yellow-Chromate-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 49/64" | MS21045-10 | 1 | 000000000 | 000000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Two-Piece-Clamp Locknuts for Extreme Vibration
Similar to steel-insert locknuts, these two-piece nuts withstand extreme vibration but are easier to install. Since the two pieces spin freely by hand until you tighten them together with a wrench, they're perfect for extra long screws and threaded rods. You can reuse them a handful of times, but their hold will decrease with repeated use. Also known as drake-style locknuts.
Height includes both nuts once assembled.
Steel
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These locknuts have equivalent strength to Grade 5 and Class 8 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. | Each | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 55/64" | 000000000 | 000000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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
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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-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.
Low-Strength Steel
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About half the strength of medium-strength steel nuts, these 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.
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.
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.
High-Strength Steel
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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-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.
Black Phosphate-Coated Steel—The dark coating creates both a finished appearance and a barrier against rust that's more durable than clear zinc plating.
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Thread Size | Wd. | Ht. | Dia. | Thk. | Fastener Strength Grade/Class | Pkg. Qty. | Pkg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zinc-Yellow-Chromate-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 11/16" | 1 21/64" | 0.1" | ASME Grade G | 10 | 000000000 | 000000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Black-Oxide Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 11/16" | 1 21/64" | 0.1" | ASME Grade G | 10 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Black Phosphate-Coated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 11/16" | 1 21/64" | 0.1" | ASME Grade G | 10 | 000000000 | 0000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||