M27 Nuts | McMaster-Carr

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

REACH Compliant

	Drive Style Drive Style

	External Hex

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

DFARS Specialty Metals
COTS-Exempt

DFARS Specialty Metals
Compliant

	Insert Maximum Temperature Insert Maximum Temperature

210° F

220° F

	OD OD

44mm

	Length Length

56 Products

About Nuts, Materials, and Finishes

Metric Medium-Strength Steel Hex Nuts—Class 8

Class 8 nuts are comparable in strength to Class 8.8 bolts and are suitable for fastening most machinery and equipment.

Metric Fine-Thread Medium-Strength
Steel Hex Nuts—Class 8

Metric High-Strength Steel Hex Nuts—Class 10

About 25% stronger than medium-strength steel nuts, these nuts are comparable in strength to class 10.9 bolts.

Metric Fine-Thread High-Strength
Steel Hex Nuts—Class 10

Closely spaced metric threads prevent these nuts from loosening due to vibration. About 25% stronger than medium-strength steel nuts, these nuts are comparable in strength to Class 10.9 bolts.

Metric Extreme-Strength Steel Hex Nuts—Class 12

These metric nuts are about 20% stronger than high strength steel nuts and are often used in heavy machinery.

Metric 18-8 Stainless Steel Hex Nuts

These nuts have good chemical resistance and may be mildly magnetic. Metric 18-8 stainless steel is also known as A2 stainless steel.

Metric Fine-Thread 18-8 Stainless Steel Hex Nuts

Metric Super-Corrosion-Resistant
316 Stainless Steel Hex Nuts

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

Metric Brass Hex Nuts

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

Thin Hex Nuts

Metric Medium-Strength Steel Thin Hex Nuts

Half as thick as regular hex nuts, these nuts fit into spaces with low height clearances. They are about half as strong as medium-strength steel, and are often used for light duty applications, such as securing access panels.

Metric Fine-Thread Medium-Strength
Steel Thin Hex Nuts

These nuts are half the height of standard hex nuts, and have closely spaced threads to prevent loosening from vibration. Half as strong as medium-strength steel nuts, they are often used for light-duty applications, such as fastening signs in place.

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

Metric 18-8 Stainless Steel Thin Hex Nuts

Useful in low-clearance applications, these metric nuts are roughly half the height of standard hex nuts, but aren’t as strong. All are 18-8 stainless steel, which is nearly as strong as steel but won’t rust in outdoor, washdown, and other corrosive environments.

Metric Fine-Thread 18-8 Stainless Steel Thin Hex Nuts

Made with fine-pitch threads, vibration is less likely to loosen these metric nuts than those with coarse-pitch threads since the threads sit closer together. Also called jam nuts, they are roughly half the height of standard hex nuts, so they’re good for applications with low clearance.

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.

Metric Super-Corrosion-Resistant
316 Stainless Steel Thin Hex Nuts

These metric nuts are made of 316 stainless steel and half as tall as regular hex nuts—use them around chemicals and salt water when space is limited.

Steel Extra-Wide Hex Nuts

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

Comparable in strength to Class 12.9 bolts.

High-Strength Steel Extra-Wide Hex Nuts

These Class 10 nuts are about 25% stronger than medium-strength steel extra-wide hex nuts.

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 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.

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.

Metric 18-8 Stainless Steel Nylon-Insert Locknuts

These metric locknuts have good chemical resistance.

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.

High-Strength Steel Top-Lock
Distorted-Thread Locknuts

Comparable in strength to Grade 8 bolts, these locknuts are about 25% stronger than medium-strength steel locknuts.

Metric Medium-Strength Steel Top-Lock
Distorted-Thread Locknuts—Class 8

These metric locknuts have an irregularly shaped thread at the top of the nut that grips the bolt for a stronger hold than nylon-insert locknuts.

Metric Medium-Strength Steel Locknuts
for use with Cotter Pins—Class 8

Secure these metric nuts by inserting a cotter pin or safety wire through the slots and a drilled hole in your bolt for mild loosening resistance. Often referred to as castle nuts.

Metric Steel-Insert Locknuts
for Extreme Vibration—Class 8

The metric steel insert grips the threads and lifts away from the nut body when installed, isolating the insert from the nut's load to resist spinoff caused by vibration.

Coupling Nuts

Metric Low-Strength Steel Coupling Nuts

For light duty applications, choose these metric-sized coupling nuts.

Metric High-Strength Steel Coupling Nuts—Class 10

These metric-sized coupling nuts are Class 10 steel, so they’re about 25% stronger than medium-strength steel coupling nuts.

Metric 18-8 Stainless Steel Coupling Nuts

These metric coupling nuts have good chemical resistance.

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.

T-Slot Fasteners and Setup Studs

T-Slot Nuts

Designed to slide into T-slot tracks on machine tool tables, use these nuts to secure clamps and workpieces.

Setup Studs

Secure setup clamps and fixtures to your machine table, or assemble heavy machines, such as engine mounts.

About Nuts, Materials, and Finishes

Hex Nuts

Metric Medium-Strength Steel Hex Nuts—Class 8

Metric Fine-Thread Medium-StrengthSteel Hex Nuts—Class 8

Metric High-Strength Steel Hex Nuts—Class 10

Metric Fine-Thread High-StrengthSteel Hex Nuts—Class 10

Metric Extreme-Strength Steel Hex Nuts—Class 12

Metric 18-8 Stainless Steel Hex Nuts

Metric Fine-Thread 18-8 Stainless Steel Hex Nuts

Metric Super-Corrosion-Resistant316 Stainless Steel Hex Nuts

Metric Brass Hex Nuts

Thin Hex Nuts

Metric Medium-Strength Steel Thin Hex Nuts

Metric Fine-Thread Medium-StrengthSteel Thin Hex Nuts

Low-Strength Steel Thin Hex Nuts

Left-Hand Threaded Low-Strength Steel Thin Hex Nuts

Metric 18-8 Stainless Steel Thin Hex Nuts

Metric Fine-Thread 18-8 Stainless Steel Thin Hex Nuts

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

Metric Super-Corrosion-Resistant316 Stainless Steel Thin Hex Nuts

Steel Extra-Wide Hex Nuts

Metric Extreme-Strength SteelExtra-Wide Hex Nuts—Grade 2H

High-Strength Steel Extra-Wide Hex Nuts

Locknuts

Metric High-Strength SteelNylon-Insert Locknuts—Class 10

Metric Medium-Strength SteelNylon-Insert Locknuts—Class 8

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

Low-Strength Steel Nylon-Insert Locknuts

Metric 18-8 Stainless Steel Nylon-Insert Locknuts

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

High-Strength Steel Top-LockDistorted-Thread Locknuts

Metric Medium-Strength Steel Top-LockDistorted-Thread Locknuts—Class 8

Metric Medium-Strength Steel Locknutsfor use with Cotter Pins—Class 8

Metric Steel-Insert Locknutsfor Extreme Vibration—Class 8

Coupling Nuts

Metric Low-Strength Steel Coupling Nuts

Metric High-Strength Steel Coupling Nuts—Class 10

Metric 18-8 Stainless Steel Coupling Nuts

Bearing Retaining Locknuts

Bearing Retaining Locknuts

T-Slot Fasteners and Setup Studs

T-Slot Nuts

Setup Studs

Metric Fine-Thread Medium-Strength
Steel Hex Nuts—Class 8

Metric Fine-Thread High-Strength
Steel Hex Nuts—Class 10

Metric Super-Corrosion-Resistant
316 Stainless Steel Hex Nuts

Metric Fine-Thread Medium-Strength
Steel Thin Hex Nuts

Metric Super-Corrosion-Resistant
316 Stainless Steel Thin Hex Nuts

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

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

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

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

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

High-Strength Steel Top-Lock
Distorted-Thread Locknuts

Metric Medium-Strength Steel Top-Lock
Distorted-Thread Locknuts—Class 8

Metric Medium-Strength Steel Locknuts
for use with Cotter Pins—Class 8

Metric Steel-Insert Locknuts
for Extreme Vibration—Class 8