1/4"-20 Jam Nuts | McMaster-Carr

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	System of Measurement System of Measurement

Inch

	Thread Size Thread Size	Show

1/4"-20

	Thread Size Thread Size	Hide

	Hex Nut Profile Hex Nut Profile


Thin	Standard

Extra-Wide Thin

	Material Material

	Finish Finish

Black Oxide

Black Ultra-Corrosion-
Resistant Coated

Zinc Yellow-Chromate Plated

Zinc-Aluminum Coated

	Height Height

	Nut Type Nut Type


Hex	Locknut

Thumb	Flange

	Thread Direction Thread Direction


Right Hand	Left Hand

	Width Width

7/16"

1/2"

9/16"

	Fastener Strength Grade/Class Fastener Strength Grade/Class

	Thread Spacing Thread Spacing

Coarse

	Specifications Met Specifications Met

	Thread Fit Thread Fit

Class 2B

Class 3B

	Drive Style Drive Style

	External Hex

	Thread Type Thread Type

UNC

	Locking Type Locking Type


Nylon Insert	Flex-Top

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

DFARS Specialty Metals
COTS-Exempt

DFARS Specialty Metals
Compliant

	Thumb Nut Profile Thumb Nut Profile


Flanged	Low

Standard

	Head Diameter Head Diameter

	Thumb Nut Head Shape Thumb Nut Head Shape


Round	Hex

	For Turnbuckle Material For Turnbuckle Material

Steel

316 Stainless Steel

	Collar Diameter Collar Diameter

	Collar Height Collar Height

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75 Products

About Nuts, Materials, and Finishes

Medium-Strength Steel Thin Hex Nuts

Made from Grade 5 steel, these inch-sized nuts are suitable for most fastening applications.

Left-Hand Threaded
Medium-Strength Steel Thin Hex Nuts

These nuts tighten when turned to the left; once fastened, they resist loosening from counterclockwise motion. They’re Grade 5 steel, so you can used these inch-sized nuts for most fastening applications.

High-Strength Steel Thin Hex Nuts—Grade 8

These nuts are about 25% stronger than medium-strength steel thin hex nuts. Available in inch thread sizes.

Low-Strength Steel Thin Hex Nuts

These nuts should be used for light duty fastening applications, such as securing access panels.

Left-Hand Threaded Low-Strength Steel Thin Hex Nuts

These nuts tighten when turned to the left; once fastened, they resist loosening from counterclockwise motion. They’re Grade 2 steel, so they can be used for fastening panels and other light duty fastening applications

18-8 Stainless Steel Thin Hex Nuts

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

Left-Hand Threaded 18-8 Stainless Steel Thin Hex Nuts

These nuts tighten when turned to the left; once fastened, they resist loosening from counterclockwise motion.

Mil. Spec. 18-8 Stainless Steel Thin Hex Nuts

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

Super-Corrosion-Resistant 316
Stainless Steel Thin Hex Nuts

These nuts have excellent chemical resistance and can be used in saltwater environments.

Left-Hand Threaded Super-Corrosion-Resistant
316 Stainless Steel Thin Hex Nuts

Made of 316 stainless steel for excellent corrosion resistance—including in salt water—these nuts tighten to the left and won’t loosen from counterclockwise motion. For use in low-clearance areas, they’re half the height of standard hex nuts.

Brass Thin Hex Nuts

These nuts are corrosion resistant in wet environments, electrically conductive, and nonmagnetic.

Left-Hand Threaded Brass Thin Hex Nuts

These nuts tighten to the left and won’t loosen from counterclockwise motion.

Plastic Thin Hex Nuts

Plastic nuts are chemical resistant, nonconductive, and lightweight.

Bronze Thin Hex Nuts

Bronze nuts are stronger and more resistant to salt water than brass nuts.

Aluminum Thin Hex Nuts

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

Titanium Thin Hex Nuts

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

Extra-Wide Thin Hex Nuts

Extreme-Strength Steel Extra-Wide
Thin Hex Nuts—Grade 2H

These nuts are often used in conjunction with an extra-wide hex nut to fasten Grade 9 bolts in heavy machinery, such as earth-moving equipment.

Low-Strength Steel Extra-Wide Thin Hex Nuts

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

Stainless Steel Extra-Wide Thin Hex Nuts

Stainless steel nuts have excellent corrosion resistance in most environments.

Brass Extra-Wide Thin Hex Nuts

Brass nuts are resistant to corrosion in wet environments and electrically conductive.

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.

High-Strength Steel Thin Nylon-Insert Locknuts

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

18-8 Stainless Steel Thin Nylon-Insert Locknuts

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

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.

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

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

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

These locknuts have good chemical resistance.

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.

Steel Thin Flex-Top Locknuts for Heavy Vibration

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

Stainless Steel Thin Flex-Top
Locknuts for Heavy Vibration

Stainless steel locknuts have excellent corrosion resistance in most environments.

Extra-Wide Thin Flex-Top Locknuts for Heavy Vibration

About half the height and 10% wider than standard flex-top locknuts, use these locknuts in low-clearance applications or jam one against an extra-wide hex nut to hold it in place.

Thumb Nuts

Steel High-Torque Low-Profile Thumb Nuts

These nuts have a black-oxide finish for mild corrosion resistance in dry environments.

Stainless Steel High-Torque Low-Profile Thumb Nuts

Stainless steel thumb nuts have excellent corrosion resistance in most environments.

Low-Profile Thumb Nuts

Use these thumb nuts in low-clearance applications or jam one against another nut to hold it in place.

18-8 Stainless Steel Flanged Knurled-Head Thumb Nuts

These thumb nuts have good chemical resistance. The flange distributes pressure over a large area to reduce stress on your part.

Super-Corrosion-Resistant 316 Stainless
Steel Flanged Knurled-Head Thumb Nuts

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

Brass Flanged Knurled-Head Thumb Nuts

These thumb nuts are corrosion resistant in wet environments, electrically conductive, and nonmagnetic. The flange distributes pressure over a large area to reduce stress on your part.

18-8 Stainless Steel Knurled-Head Thumb Nuts

These thumb nuts have good chemical resistance and may be mildly magnetic.

Super-Corrosion-Resistant 316 Stainless
Steel Knurled-Head Thumb Nuts

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

Reinforced Plastic Knurled-Head Thumb Nuts

These thumb nuts have an aluminum insert to withstand more torque than plastic thumb nuts during installation.

Plastic Knurled-Head Thumb Nuts

These nylon thumb nuts are chemical resistant, nonconductive, and lightweight.

Hex-Head Thumb Nuts

Tighten these thumb nuts with a wrench for more torque while fastening.

Jam Nuts for Turnbuckles

Tighten these jam nuts against the turnbuckle body to prevent the fitting from loosening.

About Nuts, Materials, and Finishes

Thin Hex Nuts

Medium-Strength Steel Thin Hex Nuts

Left-Hand ThreadedMedium-Strength Steel Thin Hex Nuts

High-Strength Steel Thin Hex Nuts—Grade 8

Low-Strength Steel Thin Hex Nuts

Left-Hand Threaded Low-Strength Steel Thin Hex Nuts

18-8 Stainless Steel Thin Hex Nuts

Left-Hand Threaded 18-8 Stainless Steel Thin Hex Nuts

Mil. Spec. 18-8 Stainless Steel Thin Hex Nuts

Super-Corrosion-Resistant 316Stainless Steel Thin Hex Nuts

Left-Hand Threaded Super-Corrosion-Resistant316 Stainless Steel Thin Hex Nuts

Brass Thin Hex Nuts

Left-Hand Threaded Brass Thin Hex Nuts

Plastic Thin Hex Nuts

Bronze Thin Hex Nuts

Aluminum Thin Hex Nuts

Titanium Thin Hex Nuts

Extra-Wide Thin Hex Nuts

Extreme-Strength Steel Extra-WideThin Hex Nuts—Grade 2H

Low-Strength Steel Extra-Wide Thin Hex Nuts

Stainless Steel Extra-Wide Thin Hex Nuts

Brass Extra-Wide Thin Hex Nuts

Locknuts

Low-Strength Steel Thin Nylon-Insert Locknuts

High-Strength Steel Thin Nylon-Insert Locknuts

18-8 Stainless Steel Thin Nylon-Insert Locknuts

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

Low-Strength Steel Extra-WideThin Nylon-Insert Locknuts

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

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

Steel Thin Flex-Top Locknuts for Heavy Vibration

Stainless Steel Thin Flex-TopLocknuts for Heavy Vibration

Extra-Wide Thin Flex-Top Locknuts for Heavy Vibration

Thumb Nuts

Steel High-Torque Low-Profile Thumb Nuts

Stainless Steel High-Torque Low-Profile Thumb Nuts

Low-Profile Thumb Nuts

18-8 Stainless Steel Flanged Knurled-Head Thumb Nuts

Super-Corrosion-Resistant 316 StainlessSteel Flanged Knurled-Head Thumb Nuts

Brass Flanged Knurled-Head Thumb Nuts

18-8 Stainless Steel Knurled-Head Thumb Nuts

Super-Corrosion-Resistant 316 StainlessSteel Knurled-Head Thumb Nuts

Reinforced Plastic Knurled-Head Thumb Nuts

Plastic Knurled-Head Thumb Nuts

Hex-Head Thumb Nuts

Jam Nuts for Turnbuckles

Jam Nuts for Turnbuckles

Left-Hand Threaded
Medium-Strength Steel Thin Hex Nuts

Super-Corrosion-Resistant 316
Stainless Steel Thin Hex Nuts

Left-Hand Threaded Super-Corrosion-Resistant
316 Stainless Steel Thin Hex Nuts

Extreme-Strength Steel Extra-Wide
Thin Hex Nuts—Grade 2H

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

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

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

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

Stainless Steel Thin Flex-Top
Locknuts for Heavy Vibration

Super-Corrosion-Resistant 316 Stainless
Steel Flanged Knurled-Head Thumb Nuts

Super-Corrosion-Resistant 316 Stainless
Steel Knurled-Head Thumb Nuts