Stop Nuts | McMaster-Carr

	System of Measurement System of Measurement

Inch

Metric

	Thread Size Thread Size

	Thread Pitch Thread Pitch

	Nut Type Nut Type


Locknut	Hex

Flange	Cap

Thumb	Press Fit

	Material Material

	Finish Finish

Zinc Plated

Zinc Yellow-Chromate Plated

Black Oxide

Black Phosphate

Black Zinc Plated

Corrosion-Resistant-Coated

Cadmium Yellow-Chromate
Plated

	Hex Nut Profile Hex Nut Profile


Standard	Thin

Extra-Wide Thin	High

Extra Wide

	Height Height

	Width Width

	Fastener Strength Grade/Class Fastener Strength Grade/Class

	Thread Spacing Thread Spacing

Coarse

Fine

Extra Fine

	Thread Type Thread Type

	Thread Fit Thread Fit

	Insert Maximum Temperature Insert Maximum Temperature

	Specifications Met Specifications Met

	RoHS (Restriction of Hazardous Substances) RoHS (Restriction of Hazardous Substances)

RoHS Compliant

RoHS Compliant with
Exemptions

	REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

REACH Compliant

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

DFARS Specialty Metals
Compliant

	OD OD

	Flange Diameter Flange Diameter

	Flange Thickness Flange Thickness

	Thread Depth Thread Depth

	Cap Color Cap Color

	Black
	Gray

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994 Products

About Nuts, Materials, and Finishes

Medium-Strength Steel Nylon-Insert Locknuts—Grade 5

Made from Grade 5 steel, these inch-sized locknuts are suitable for fastening most machinery and equipment.

Metric Medium-Strength Steel
Nylon-Insert Locknuts—Class 8

Made from medium-strength steel with a nylon insert, these Class 8 metric locknuts are strong enough to use on most machinery and equipment that’s prone to vibration and temperature changes.

Metric Fine-Thread Medium-Strength
Steel Nylon-Insert Locknuts—Class 8

Get a grip on metric bolts exposed to vibration, wear, and changes in temperature. These metric locknuts have a nylon insert that holds onto bolts without damaging their threads.

High-Strength Steel Nylon-Insert Locknuts—Grade 8

Includes inch thread sizes. These Grade 8 steel locknuts are 25% stronger than our medium-strength steel nylon-insert locknuts.

Metric High-Strength Steel
Nylon-Insert Locknuts—Class 10

A nylon insert keeps metric bolt threads from coming loose due to vibration, wear, and temperature swings. About 25% stronger than medium-strength steel locknuts, these nuts are made of high-strength, Class 10 steel.

Metric Fine-Thread High-Strength
Steel Nylon-Insert Locknuts—Class 10

Closely spaced metric threads prevent loosening from vibration. These Class 10 steel locknuts are 25% stronger than our medium-strength steel nylon-insert locknuts.

Low-Strength Steel Nylon-Insert Locknuts

Made from low-strength steel, these locknuts should be used for light duty fastening applications, such as securing.access panels.

Mil. Spec. Low-Strength Steel Nylon-Insert Locknuts

Choose these locknuts for their adherence to strict military standards for material and construction. They’re low-strength steel, so they should be used for fastening panels and other light duty fastening applications.

18-8 Stainless Steel Nylon-Insert Locknuts

These locknuts have good chemical resistance.

Metric 18-8 Stainless Steel Nylon-Insert Locknuts

These metric locknuts have good chemical resistance.

Mil. Spec. 18-8 Stainless Steel Nylon-Insert Locknuts

Choose these locknuts for their adherence to strict military standards for material and construction.

Super-Corrosion-Resistant 316
Stainless Steel Nylon-Insert Locknuts

More corrosion resistant than 18-8 stainless steel locknuts, these locknuts have excellent resistance to chemicals and salt water.

Metric Super-Corrosion-Resistant 316
Stainless Steel Nylon-Insert Locknuts

More corrosion resistant than 18-8 stainless steel locknuts, these metric locknuts have excellent resistance to chemicals and salt water.

Brass Nylon-Insert Locknuts

Brass locknuts are corrosion resistant in wet environments and electrically conductive.

Aluminum Nylon-Insert Locknuts

One-third the weight of steel, aluminum locknuts resist corrosion in wet environments.

Titanium Nylon-Insert Locknuts

Titanium locknuts have a high strength-to-weight ratio and are resistant to acids and salt water.

Thin Nylon-Insert Locknuts

Low-Strength Steel Thin Nylon-Insert Locknuts

These locknuts are about half the height of standard nylon-insert locknuts. Use them in light duty low clearance applications or jam one against a hex nut to hold it in place.

Metric Low-Profile Low-Strength
Steel Nylon-Insert Locknuts

With a shorter hex height than standard DIN 985 locknuts, these nylon-insert locknuts meet international ISO 10511 dimensional standards and are easy to install in tight spaces.

Mil. Spec. Low-Strength Steel
Thin Nylon-Insert Locknuts

Choose these locknuts for their adherence to strict military standards for material and construction.

High-Strength Steel Thin Nylon-Insert Locknuts

These Grade 8 locknuts are about 25% stronger than medium-strength steel thin locknuts.

Medium-Strength Steel Thin Nylon-Insert Locknuts

Grade 5 locknuts are suitable for fastening most machinery and equipment when used in conjunction with a standard hex nut.

18-8 Stainless Steel Thin Nylon-Insert Locknuts

These locknuts have good chemical resistance and may be mildly magnetic.

Mil. Spec. 18-8 Stainless Steel
Thin Nylon-Insert Locknuts

Choose these locknuts for their adherence to strict military standards for material and construction.

Super-Corrosion-Resistant 316 Stainless
Steel Thin Nylon-Insert Locknuts

More corrosion resistant than 18-8 stainless steel locknuts, these have excellent resistance to chemicals and salt water.

Extra-Wide Thin Nylon-Insert Locknuts

High-Strength Steel Extra-Wide
Thin Nylon-Insert Locknuts

Comparable in strength to Grade 8 bolts, these locknuts are about three times stronger than low-strength steel extra-wide thin locknuts.

Low-Strength Steel Extra-Wide
Thin Nylon-Insert Locknuts

Use these locknuts for light duty fastening applications, such as securing access panels.

Super-Corrosion-Resistant 316 Stainless
Steel Extra-Wide Thin Nylon-Insert Locknuts

More corrosion resistant than 18-8 stainless steel locknuts, these have excellent resistance to chemicals and salt water.

18-8 Stainless Steel Extra-Wide
Thin Nylon-Insert Locknuts

These locknuts have good chemical resistance.

Extra-Wide Nylon-Insert Locknuts

Super-Corrosion-Resistant 316 Stainless
Steel Extra-Wide Nylon-Insert Locknuts

More corrosion resistant than 18-8 stainless steel locknuts, these have excellent resistance to chemicals and salt water.

Steel Extra-Wide Nylon-Insert Locknuts

Known for their strength, these locknuts are zinc-plated to resist corrosion in wet environments.

18-8 Stainless Steel Extra-Wide Nylon-Insert Locknuts

These locknuts have good chemical resistance.

Nylon-Insert Flange Locknuts

Metric Stainless Steel Nylon-Insert Flange Locknuts

Stainless Steel Nylon-Insert Flange Locknuts

Medium-Strength Steel Nylon-Insert
Flange Locknuts—Grade F

Grade F nuts are comparable in strength to Grade 5 bolts.

Metric Medium-Strength Steel
Nylon-Insert Flange Locknuts—Class 8

High-Strength Steel Nylon-Insert
Flange Locknuts—Grade G

Grade G nuts are comparable in strength to Grade 8 bolts.

Metric High-Strength Steel Nylon-Insert
Flange Locknuts—Class 10

Cap Locknuts

Nylon-Insert Cap Locknuts

The nylon cap covers and grips the threads to resist loosening.

Metric Nylon-Insert Cap Locknuts

A nylon insert on these metric nuts prevents vibration from loosening them, and a domed head protects the threads at the end of the bolt from damage and debris.

Nylon-Insert Wing Locknuts

A nylon insert grips threads to resist loosening.

Nylon-Insert Press-Fit Locknuts for Sheet Metal

These press-fit nuts have a nylon insert that grips threads to resist loosening.

Nylon-Insert Locknut Assortments

A nylon insert grips threads to resist loosening.

Bearing Retaining Locknuts

With a nylon insert that grips your threaded shaft or spindle without damaging its threads, these locknuts—also called shaft nuts—hold bearings, bushings, gears, and pulleys prone to vibration tightly in place.

About Nuts, Materials, and Finishes

Nylon-Insert Locknuts

Medium-Strength Steel Nylon-Insert Locknuts—Grade 5

Metric Medium-Strength SteelNylon-Insert Locknuts—Class 8

Metric Fine-Thread Medium-StrengthSteel Nylon-Insert Locknuts—Class 8

High-Strength Steel Nylon-Insert Locknuts—Grade 8

Metric High-Strength SteelNylon-Insert Locknuts—Class 10

Metric Fine-Thread High-StrengthSteel Nylon-Insert Locknuts—Class 10

Low-Strength Steel Nylon-Insert Locknuts

Mil. Spec. Low-Strength Steel Nylon-Insert Locknuts

18-8 Stainless Steel Nylon-Insert Locknuts

Metric 18-8 Stainless Steel Nylon-Insert Locknuts

Mil. Spec. 18-8 Stainless Steel Nylon-Insert Locknuts

Super-Corrosion-Resistant 316Stainless Steel Nylon-Insert Locknuts

Metric Super-Corrosion-Resistant 316Stainless Steel Nylon-Insert Locknuts

Brass Nylon-Insert Locknuts

Aluminum Nylon-Insert Locknuts

Titanium Nylon-Insert Locknuts

Thin Nylon-Insert Locknuts

Low-Strength Steel Thin Nylon-Insert Locknuts

Metric Low-Profile Low-StrengthSteel Nylon-Insert Locknuts

Mil. Spec. Low-Strength SteelThin Nylon-Insert Locknuts

High-Strength Steel Thin Nylon-Insert Locknuts

Medium-Strength Steel Thin Nylon-Insert Locknuts

18-8 Stainless Steel Thin Nylon-Insert Locknuts

Mil. Spec. 18-8 Stainless SteelThin Nylon-Insert Locknuts

Super-Corrosion-Resistant 316 StainlessSteel Thin Nylon-Insert Locknuts

Extra-Wide Thin Nylon-Insert Locknuts

High-Strength Steel Extra-WideThin Nylon-Insert Locknuts

Low-Strength Steel Extra-WideThin Nylon-Insert Locknuts

Super-Corrosion-Resistant 316 StainlessSteel Extra-Wide Thin Nylon-Insert Locknuts

18-8 Stainless Steel Extra-WideThin Nylon-Insert Locknuts

Extra-Wide Nylon-Insert Locknuts

Super-Corrosion-Resistant 316 StainlessSteel Extra-Wide Nylon-Insert Locknuts

Steel Extra-Wide Nylon-Insert Locknuts

18-8 Stainless Steel Extra-Wide Nylon-Insert Locknuts

Nylon-Insert Flange Locknuts

Metric Stainless Steel Nylon-Insert Flange Locknuts

Stainless Steel Nylon-Insert Flange Locknuts

Medium-Strength Steel Nylon-InsertFlange Locknuts—Grade F

Metric Medium-Strength SteelNylon-Insert Flange Locknuts—Class 8

High-Strength Steel Nylon-InsertFlange Locknuts—Grade G

Metric High-Strength Steel Nylon-InsertFlange Locknuts—Class 10

Cap Locknuts

Nylon-Insert Cap Locknuts