All-Metal Locknuts | McMaster-Carr

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Cadmium Yellow-Chromate Plated

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DFARS Specialty Metals

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Unified Standard Class 2B

Unified Standard Class 3B

Flange Diameter

1,379 Products

Locknuts

Nylon-Insert Locking About Nylon-Insert Locking

Thin-Profile Nylon-Insert Locknuts

About half the height of standard nuts to fit in spaces with low clearance

7 products

Distorted-Thread Locking About Distorted-Thread Locking

Top-Lock Distorted-Thread Locknuts

Irregularly shaped threads at the top grip screws tighter than a nylon insert

285 products

Center-Lock Distorted-Thread Locknuts

Thread on from either side so there’s no risk of damaging screws

86 products

Left-Hand-Thread Center-Lock Distorted-Thread Locknuts

Secure parts that rotate counterclockwise, such as the propeller on a mixer

6 products

Lock Washer About Lock Washer

Locknuts with External-Tooth Lock Washer

Twist into place by hand to save on assembly time

56 products

Narrow-Profile Locknuts with External-Tooth Lock Washer

20% narrower than other nuts to fit in cramped spaces

3 products

Locknuts with Spring-Lock Washer

Grip more tightly than external-tooth washers to better resist vibration

21 products

Assortments of Locknuts with External-Tooth Lock Washer

A range of sizes to fasten a variety of parts

2 products

Cotter-Pin Lockable About Cotter-Pin Lockable

Locknuts for use with Cotter Pins

Secure rotating parts subjected to mild vibration, such as wheels on carts

98 products

Flex-Top Locking About Flex-Top Locking

Flex-Top Locknuts for Heavy Vibration

Stronger hold than nylon-insert and distorted-thread locknuts

87 products

Thin-Profile Flex-Top Locknuts for Heavy Vibration

About two-thirds the height of standard nuts to fit in spaces with low clearance

58 products

Heavy-Profile Flex-Top Locknuts for Heavy Vibration

About 10% wider and taller than standard nuts to handle heavier loads

13 products

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

Fit in low-clearance spaces and handle heavier loads than standard nuts

9 products

Mil. Spec. Flex-Top Locknuts for Heavy Vibration

Meet strict U.S. military standards for material and construction

18 products

Steel-Insert Locking About Steel-Insert Locking

Steel-Insert Locknuts for Extreme Vibration

The most vibration-resistant hold we offer

16 products

Thin-Profile Steel-Insert Locknuts for Extreme Vibration

About two-thirds the height of standard nuts to fit in spaces with low clearance

9 products

Heavy-Profile Steel-Insert Locknuts for Extreme Vibration

About 10% wider and taller than standard nuts to handle heavier loads

19 products

Two-Piece-Clamp Locking About Two-Piece-Clamp Locking

Two-Piece-Clamp Locknuts for Extreme Vibration

8 products

Spring-Stop Locking About Spring-Stop Locking

Spring-Stop Locknuts

Withstand heavy vibration similar to distorted-thread nuts and are reusable

10 products

Serration Locking About Serration Locking

Serrated Locknuts

Easiest to install but least effective against vibration

7 products

Other Products

Flange Nuts

The flange distributes pressure, so you don't need a washer

318 products

Conduit Locknuts

Secure threaded conduit fittings to knockouts in electrical boxes

58 products

Tamper-Resistant Nuts

Hard to detach without special tools to prevent unwanted removal

3 products

Pipe Locknuts

Thread onto the male end of a pipe fitting so it won't loosen from vibration

97 products

Weld Nuts

Weld to metal surfaces to add permanent threads

22 products

Cap Nuts

Cover and protect threads while adding a finished look; also known as acorn nuts

32 products

Rivet Nuts

Add threads to thin panels with access from only one side; also known as blind inserts

13 products

Press-Fit Nuts

Push into drilled or punched holes to add threads to thin panels

17 products