4-40 Locknuts | McMaster-Carr

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System of Measurement

Nut Type

Material

Grade 5 Titanium

Stainless Steel

Locking Type

Distorted Thread

Hex Nut Profile

Height

Finish

Black Zinc Plated

Cadmium Yellow-Chromate Plated

Width

Thread Type

Performance

Corrosion Resistant

High Temperature

Vibration Resistant

Washer Material

400 Series Stainless Steel

Thread Direction

Specifications Met

Military Specification

Thread Spacing

Sold As

Fastener Strength Rating

Thread Fit

Unified Standard Class 2B

Unified Standard Class 3B

Flange Diameter

Washer Type

DFARS Specialty Metals

Flange Thickness

Export Control Classification Number (ECCN)

REACH

RoHS

Compliant with Exemptions

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34 Products

Locknuts

Nylon-Insert Locking About Nylon-Insert Locking

About Nylon-Insert Locking

Nylon-Insert Locknuts

Nylon-Insert Locknuts

Versatile and economical—the most commonly used locknuts

Thin-Profile Nylon-Insert Locknuts

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

Mil. Spec. Nylon-Insert Locknuts

Mil. Spec. Nylon-Insert Locknuts

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

Mil. Spec. Thin-Profile Nylon-Insert Locknuts

Meet U.S. military standards and are half the height of standard nuts to fit in low-clearance spaces

Nylon-Insert Locknut Assortments

Nylon-Insert Locknut Assortments

A range of sizes to fasten a variety of parts

Lock Washer About Lock Washer

About Lock Washer

Locknuts with External-Tooth Lock Washer

Locknuts with External-Tooth Lock Washer

Twist into place by hand to save on assembly time

Locknuts with Spring-Lock Washer

Locknuts with Spring-Lock Washer

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

Assortments of Locknuts with External-Tooth Lock Washer

Assortments of Locknuts with External-Tooth Lock Washer

A range of sizes to fasten a variety of parts

Flex-Top Locking About Flex-Top Locking

About Flex-Top Locking

Flex-Top Locknuts for Heavy Vibration

Flex-Top Locknuts for Heavy Vibration

Stronger hold than nylon-insert and distorted-thread locknuts

Mil. Spec. Flex-Top Locknuts for Heavy Vibration

Mil. Spec. Flex-Top Locknuts for Heavy Vibration

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

Thread-Forming Lock About Thread-Forming Lock

About Thread-Forming Lock

Thread-Forming Locknuts

Thread-Forming Locknuts

Form threads into these nuts for a tight fit that won't loosen under vibration

Other Products

Flange Nuts

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

Cap Nuts

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

Press-Fit Nuts

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

The quick brown fox jumped over the lazy dog. Pedestal (35" Ht. x 4" Wd. x 4" Dp.)