Brass Pipe Locknuts | McMaster-Carr

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	Material Material	Show

Brass

	Material Material	Hide

	Pipe Size Pipe Size

	Thread Type Thread Type

	System of Measurement System of Measurement

Inch

Metric

	Thread Size Thread Size

	For Use With For Use With

	Length Length

	For Pipe Material For Pipe Material

Brass

	Hex Width Hex Width

	Nut Type Nut Type


Panel	Hex

	For Pipe Schedule For Pipe Schedule

	40

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

DFARS Specialty Metals
COTS-Exempt

	Maximum Pressure Maximum Pressure

200 psi @ 72° F

1,000 psi @ 72° F

Not Rated

	Width Width

	Height Height

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

RoHS Compliant

RoHS Compliant with
Exemptions

	Specifications Met Specifications Met

	Pressure Class Pressure Class

125

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

REACH Compliant

	Finish Finish

Chrome Plated

Nickel Plated

	Panel Nut Shape Panel Nut Shape

	Hex

	Fabrication Fabrication

Machined

	Thread Fit Thread Fit

Class 2B

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59 Products

About Conduit

How to Identify and Measure Fittings

Pipe size is an industry designation, not the actual size. View information about how to measure threaded and unthreaded pipe and pipe fittings.

About Nuts, Materials, and Finishes

Low-Pressure Brass and Bronze Threaded Pipe Fittings

Use these fittings in low-pressure flow applications. They have good corrosion resistance. Fittings rated for use with drinking water meet NSF/ANSI 61 safety standards.

Locknuts thread onto the male end of a fitting to provide extra holding power so the fitting won’t loosen from vibration. Locknuts that meet DIN 431 adhere to international standards for locknut dimensions.

NPSL (National Pipe Straight Locknut) threads are compatible with NPT threads.

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

Locknuts

For Use With: See table
Pressure Class: See table
Specifications Met: See table
Pipe Nipples and Pipe: See table
Flanges: See table

				For Pipe		For Flange
Pipe Size	Max. Pressure	Pressure Class	Material	Schedule	Material	Class	Material	For Use With	Specifications Met		Each
NPSL Female
1/8	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Drinking Water, Natural Gas, Oil	ASME B1.20.1, ASME B16.15, ASTM A584, NSF/ANSI 61	00000000	00000
1/4	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Drinking Water, Natural Gas, Oil	ASME B1.20.1, ASME B16.15, ASTM A584, NSF/ANSI 61	00000000	0000
3/8	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Drinking Water, Natural Gas, Oil	ASME B1.20.1, ASME B16.15, ASTM A584, NSF/ANSI 61	00000000	0000
1/2	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Drinking Water, Natural Gas, Oil	ASME B1.20.1, ASME B16.15, ASTM A584, NSF/ANSI 61	00000000	0000
3/4	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Drinking Water, Natural Gas, Oil	ASME B1.20.1, ASME B16.15, ASTM A584, NSF/ANSI 61	00000000	0000
1	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Drinking Water, Natural Gas, Oil	ASME B1.20.1, ASME B16.15, ASTM A584, NSF/ANSI 61	00000000	0000
1 1/4	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Drinking Water, Natural Gas, Oil	ASME B1.20.1, ASME B16.15, ASTM A584, NSF/ANSI 61	00000000	00000
1 1/2	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Drinking Water, Natural Gas, Oil	ASME B1.20.1, ASME B16.15, ASTM A584, NSF/ANSI 61	00000000	00000
2	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Drinking Water, Natural Gas, Oil	ASME B1.20.1, ASME B16.15, ASTM A584, NSF/ANSI 61	00000000	00000
2 1/2	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Natural Gas, Oil	ASME B16.15	00000000	00000
3	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Natural Gas, Oil	ASME B16.15	00000000	000000
4	200 psi @ 72° F	125	Brass	40	Brass	150	Brass	Air, Natural Gas, Oil	ASME B16.15	00000000	000000
BSPP Female
1/8	Not Rated	__	Brass	__	Brass	__	Brass	Air, Natural Gas, Oil	DIN 431	0000000	0000
1/4	Not Rated	__	Brass	__	Brass	__	Brass	Air, Natural Gas, Oil	DIN 431	0000000	0000
3/8	Not Rated	__	Brass	__	Brass	__	Brass	Air, Natural Gas, Oil	DIN 431	0000000	0000
1/2	Not Rated	__	Brass	__	Brass	__	Brass	Air, Natural Gas, Oil	DIN 431	0000000	0000
3/4	Not Rated	__	Brass	__	Brass	__	Brass	Air, Natural Gas, Oil	DIN 431	0000000	0000
1	Not Rated	__	Brass	__	Brass	__	Brass	Air, Natural Gas, Oil	DIN 431	0000000	00000
1 1/4	Not Rated	__	Brass	__	Brass	__	Brass	Air, Natural Gas, Oil	DIN 431	0000000	00000
1 1/2	Not Rated	__	Brass	__	Brass	__	Brass	Air, Natural Gas, Oil	DIN 431	0000000	00000

Low-Pressure Plated Brass Threaded Pipe Fittings

Used in low-pressure pipe lines, these brass fittings have a plating that makes them shiny and improves corrosion resistance.

Chrome-plated brass fittings are shinier and withstand corrosion better than nickel-plated brass fittings.

Locknuts thread onto the male end of a fitting to provide extra holding power so the fitting won’t loosen from vibration.

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

Locknuts

For Use With: Air, Natural Gas, Oil, Steam, Water
Pressure Class: 125
Specifications Met: ASTM B456
Pipe Nipples and Pipe: Use Schedule 40 brass

NPT Female
Pipe Size	Max. Pressure	Max. Steam Pressure		Each
Chrome-Plated Brass
1/8	200 psi @ 72° F	125 psi @ 400° F	00000000	000000
1/4	200 psi @ 72° F	125 psi @ 400° F	00000000	00000
3/8	200 psi @ 72° F	125 psi @ 400° F	00000000	00000
1/2	200 psi @ 72° F	125 psi @ 400° F	00000000	00000
3/4	200 psi @ 72° F	125 psi @ 400° F	00000000	00000
1	200 psi @ 72° F	125 psi @ 400° F	00000000	00000

High-Pressure Brass Threaded Pipe Fittings

These fittings have the strength to handle high-pressure applications. They are brass for good corrosion resistance.

Locknuts thread onto the male end of a fitting to provide extra holding power so the fitting won’t loosen from vibration.

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

Locknuts

For Use With: Air, Natural Gas, Oil, Water

NPT Female
Pipe Size	Max. Pressure		Each
1/8	1,000 psi @ 72° F	000000000	00000
1/4	1,000 psi @ 72° F	000000000	0000
3/8	1,000 psi @ 72° F	000000000	0000
1/2	1,000 psi @ 72° F	000000000	0000
3/4	1,000 psi @ 72° F	000000000	0000

Locknuts for Metal Conduit Fittings

Brass

Secure threaded metal conduit fittings to a knockout in an outlet box or enclosure.

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

Brass
Thread Size	Specifications Met		Each
Metric Threads
M12	DIN EN 60204	0000000	00000
M16	DIN EN 60204	0000000	0000
M20	DIN EN 60204	0000000	0000
M25	DIN EN 60204	00000000	0000
M32	DIN EN 60204	0000000	0000
M40	DIN EN 60204	0000000	00000
M50	DIN EN 60204	0000000	00000
M63	DIN EN 60204	00000000	00000

Brass Hex Panel Nuts

These panel nuts are corrosion resistant in wet environments, electrically conductive, and nonmagnetic. They can be fastened with a wrench for more torque while tightening than knurled panel nuts. Also known as dress nuts, they're extremely thin for use in tight spaces such as electrical panels.

Nickel-plated brass panel nuts have excellent resistance to chemicals and salt water.

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

NPSM Threads

Brass
Pipe Size	Wd.	Ht.	Pkg. Qty.		Pkg.
1/8	5/8"	1/8"	1	000000000	00000
1/8	5/8"	3/16"	1	000000000	0000
Nickel-Plated Brass
1/8	1/2"	1/8"	10	000000000	0000

UNEF Threads

Brass
Thread Size	Wd.	Ht.	Pkg. Qty.		Pkg.
1/4"-32	5/16"	5/64"	10	000000000	00000
1/4"-32	3/8"	3/32"	10	000000000	0000
5/16"-32	7/16"	7/64"	10	000000000	0000
3/8"-32	5/8"	3/32"	1	000000000	0000
7/16"-28	5/8"	3/32"	1	000000000	0000
15/32"-32	5/8"	3/32"	1	000000000	0000
Nickel-Plated Brass
1/4"-32	5/16"	5/64"	10	000000000	0000
1/4"-32	3/8"	3/32"	10	000000000	0000
5/16"-32	7/16"	7/64"	10	000000000	0000
3/8"-32	1/2"	3/32"	10	000000000	0000
7/16"-28	5/8"	3/32"	1	000000000	0000
15/32"-32	9/16"	5/64"	10	000000000	0000
15/32"-32	9/16"	3/32"	10	000000000	0000
1/2"-28	5/8"	1/8"	10	000000000	0000

UNS Threads

Brass
Thread Size	Wd.	Ht.	Pkg. Qty.		Pkg.
5/8"-27	3/4"	1/8"	1	000000000	00000
Nickel-Plated Brass
1/4"-40	5/16"	1/16"	10	000000000	0000
5/8"-27	3/4"	1/8"	1	000000000	0000