McMaster-Carr

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	System of Measurement System of Measurement

Inch

Metric

	Thread Size Thread Size	Show

M16

	Thread Size Thread Size	Hide

	Thread Pitch Thread Pitch

2 mm

	Material Material

Aluminum

Stainless Steel

Steel

	Pitch Pitch

1.75 mm

2 mm

	Thread Length Thread Length

1/2"

12mm

16mm

	Gender Gender

	Female

	Nut Type Nut Type


Coupling	Hex

	Hex Length Hex Length

54 mm

	Hex Size Hex Size

21 mm

	Width Width

24 mm

27 mm

	Shape Shape


Hex	Round

	Thread Fit Thread Fit

Class 2B

Class 6H

	Length Length

	Drive Style Drive Style

	External Hex

	Thread Type Thread Type

Metric

	Specifications Met Specifications Met

ASTM

DIN

FDA Compliant

	Tensile Strength Tensile Strength

20,000 to 49,999 psi

50,000 to 99,999 psi

Not Rated

	For Adapting For Adapting

Thread Size

	Hardness Hardness

	Finish Finish

Zinc Plated

Black Oxide

	Threading Threading

	Fully Threaded
	Partially Threaded

	Thread Direction Thread Direction

	Right Hand

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23 Products

About Nuts, Materials, and Finishes

Mount components onto food processing lines, walls, and sanitary equipment while leaving space to clean in between. These standoffs have a smooth finish and rounded edges to eliminate pits or crevices where bacteria could grow. Made of 18-8 stainless steel, they won’t corrode from frequent washdowns with harsh cleaners and sanitizers. A TPE rubber seal stops water and contaminants from entering the body of these standoffs. They are FDA compliant, meaning they are safe for contact with food. Use the included locknut and washer to mount these standoffs to an enclosure, and use the internal threads to fasten them to machines, walls, or other surfaces.

For technical drawings and 3-D models, click on a part number.

	Thread (A)			Thread (B)
Lg., mm	Size	Pitch, mm.	Lg., mm	Size	Pitch, mm	Min. Lg., mm	Specifications Met		Each
18-8 Stainless Steel
33.7 mm OD
50	M16	1.5	11.5	M10	1.25	15	FDA Compliant 21 CFR 177.2600	000000000	000000

Metric-to-Metric Female Hex Thread Adapters

Increase or decrease metric thread size from one male-threaded part to another. Commonly used to connect two differently sized threaded rods, they have a hex-shaped body, so you can tighten them with a standard wrench. You can also use these adapters to change thread pitch or convert a male-threaded connection to a female-threaded connection. Small adapters can work as threaded standoffs, positioning and separating circuit boards and other components in assemblies.

At about a third of the weight of steel adapters, aluminum adapters are the lightest we offer. They resist corrosion in wet environments.

18-8 stainless steel adapters resist corrosion caused by water. They're good for wet and damp environments but will corrode when exposed to salt water and other chloride solutions.

316 stainless steel adapters have the best corrosion resistance. They stand up to wet environments, just like 18-8 stainless steel adapters, but unlike 18-8 stainless steel adapters, they resist corrosion caused by salt water and harsh chemicals.

For technical drawings and 3-D models, click on a part number.

Thread Size				Thread Lg.		Thread Fit		Hex					Each
(A)	Pitch (A), mm	(B)	Pitch (B), mm	(A), mm	(B), mm	(A)	(B)	Size, mm	Lg., mm	Specifications Met	Hardness		1-9	10-Up
Aluminum
M12	1.75	M16	2	12	16	Class 6H	Class 6H	21	54	ASTM B211	Rockwell B56	000000000	000000	000000
18-8 Stainless Steel
M12	1.75	M16	2	12	16	Class 6H	Class 6H	21	54	ASTM A582	Rockwell B80	000000000	00000	00000
316 Stainless Steel
M12	1.75	M16	2	12	16	Class 6H	Class 6H	21	54	ASTM A276	Rockwell B83	000000000	00000	00000

Inch-to-Metric Female Hex Thread Adapters

Adapt threaded rods from inch to metric. These adapters connect two male-threaded fasteners, so you can change the gender of a mating part or increase or decrease its thread size. The hex-shaped body fits into the head of a standard wrench. Small adapters can also be used as standoffs, positioning and separating circuit boards and other components in assemblies.

18-8 stainless steel adapters resist corrosion caused by water. They're good for wet and damp environments but will corrode when exposed to salt water and other chloride solutions.

At about a third of the weight of steel adapters, aluminum adapters are the lightest we offer. They resist corrosion in wet environments.

For technical drawings and 3-D models, click on a part number.

Thread Size			Thread Lg.		Thread Fit		Hex						Each
(A)	(B)	Pitch (B), mm	(A)	(B), mm	(A)	(B)	Size	Lg.	Specifications Met	Tensile Strength, psi	Hardness		1-9	10-Up
18-8 Stainless Steel
1/2"-13	M16	2	1/2"	16	Class 2B	Class 6H	21mm	54mm	ASTM A582	85,000	Rockwell B80	000000000	000000	000000
1/2"-20	M16	2	1/2"	16	Class 2B	Class 6H	21mm	54mm	ASTM A582	85,000	Rockwell B80	000000000	00000	00000
1/2"-28	M16	2	1/2"	16	Class 2B	Class 6H	21mm	54mm	ASTM A582	85,000	Rockwell B80	000000000	00000	00000
316 Stainless Steel
1/2"-13	M16	2	1/2"	16	Class 2B	Class 6H	21mm	54mm	ASTM A276	75,000	Rockwell B83	000000000	00000	00000
1/2"-20	M16	2	1/2"	16	Class 2B	Class 6H	21mm	54mm	ASTM A276	75,000	Rockwell B83	000000000	00000	00000
1/2"-28	M16	2	1/2"	16	Class 2B	Class 6H	21mm	54mm	ASTM A276	75,000	Rockwell B83	000000000	00000	00000
Aluminum
1/2"-13	M16	2	1/2"	16	Class 2B	Class 6H	21mm	54mm	ASTM B211	45,000	Rockwell B56	000000000	00000	00000
1/2"-20	M16	2	1/2"	16	Class 2B	Class 6H	21mm	54mm	ASTM B211	45,000	Rockwell B56	000000000	00000	0000
1/2"-28	M16	2	1/2"	16	Class 2B	Class 6H	21mm	54mm	ASTM B211	45,000	Rockwell B56	000000000	00000	00000

Metric 18-8 Stainless Steel Coupling Nuts

Stainless Steel

Black-Oxide Stainless Steel

Made from 18-8 stainless steel, these metric coupling nuts have good chemical resistance and may be mildly magnetic. Also known as extension nuts, use them to connect and extend threaded rods.

Coupling nuts with a black-oxide finish have a dark surface color.

For technical drawings and 3-D models, click on a part number.

Thread						Each
Size	Pitch, mm	Lg., mm	Wd., mm	Specifications Met		1-9	10-Up
18-8 Stainless Steel
M16	2	48	24	DIN 6334	000000000	000000	00000
Black-Oxide 18-8 Stainless Steel
M16	2	48	24	DIN 6334	000000000	00000	00000

Metric Super-Corrosion-Resistant
316 Stainless Steel Coupling Nuts

Made from 316 stainless steel, these coupling have excellent resistance to chemicals and salt water. Also known as extension nuts, use them to connect and extend threaded rods. They may be mildly magnetic.

For technical drawings and 3-D models, click on a part number.

Thread						Each
Size	Pitch, mm	Lg., mm	Wd., mm	Specifications Met		1-9	10-Up
316 Stainless Steel
M16	2	48	24	DIN 6334	000000000	000000	000000

Metric Low-Strength Steel Coupling Nuts

Often referred to as extension nuts, use these to connect and extend threaded rods. They're about half the strength of medium-strength steel coupling nuts for use in light duty fastening applications.

Zinc-plated steel coupling nuts resist corrosion in wet environments.

Black-oxide steel coupling nuts have a dark surface color and are mildly corrosion resistant in dry environments.

For technical drawings and 3-D models, click on a part number.

Thread						Each
Size	Pitch, mm	Lg., mm	Wd., mm	Specifications Met		1-9	10-Up
Zinc-Plated Steel
M16	2	48	24	DIN 6334	000000000	00000	00000
Black-Oxide Steel
M16	2	40	27	__	000000000	0000	0000

Metric Medium-Strength Steel Coupling Nuts—Class 8

Often referred to as extension nuts, use these to connect and extend threaded rods. They're comparable in strength to Class 8.8 bolts.

Zinc-plated steel coupling nuts resist corrosion in wet environments.

Black-oxide steel coupling nuts have a dark surface color and are mildly corrosion resistant in dry environments.

For technical drawings and 3-D models, click on a part number.

Thread						Each
Size	Pitch, mm	Lg., mm	Wd., mm	Specifications Met		1-9	10-Up
Zinc-Plated Steel—Class 8
M16	2	48	24	DIN 6334	000000000	00000	00000
Black-Oxide Steel—Class 8
M16	2	48	24	DIN 6334	000000000	00000	00000

Stainless Steel Extra-Long Coupling Nuts

These coupling nuts have good chemical resistance. Also known as sleeve nuts, they're at least twice the length of standard coupling nuts to provide more room to connect and extend long lengths of threaded rods.

For technical drawings and 3-D models, click on a part number.

Metric

Thread							Each
Size	Pitch, mm	Lg., mm	Wd., mm	Threading	Min. Thread Lg., mm		1-9	10-Up
18-8 Stainless Steel
M16	2	96	24	Partially Threaded	16	000000000	0000000	000000

Round Coupling Nuts

With a smooth rounded body for a finished look, use these nuts to connect and extend threaded rods. Made from 18-8 stainless steel, they have good chemical resistance.

For technical drawings and 3-D models, click on a part number.

Thread						Each
Size	Pitch, mm	Lg., mm	OD, mm	Specifications Met		1-9	10-Up
18-8 Stainless Steel
M16	2	40	22	DIN 88088	000000000	00000	00000

Metric Steel High Hex Nuts

These nuts are 50% taller than standard hex nuts and provide a larger gripping area for installation with a wrench. They're zinc plated to resist corrosion in wet environments.

For technical drawings and 3-D models, click on a part number.

Thread
Size	Pitch, mm	Wd., mm	Ht., mm	Pkg. Qty.		Pkg.
Zinc-Plated Steel—Class 8
M16	2	24	16	10	000000000	000000

Terms and Conditions and Privacy Policy

About Nuts, Materials, and Finishes

Sanitary Threaded Standoffs

Metric-to-Metric Female Hex Thread Adapters

Inch-to-Metric Female Hex Thread Adapters

Metric 18-8 Stainless Steel Coupling Nuts

Metric Super-Corrosion-Resistant316 Stainless Steel Coupling Nuts

Metric Low-Strength Steel Coupling Nuts

Metric Medium-Strength Steel Coupling Nuts—Class 8

Stainless Steel Extra-Long Coupling Nuts

Round Coupling Nuts

Metric Steel High Hex Nuts

Metric Super-Corrosion-Resistant
316 Stainless Steel Coupling Nuts