3/8 Flanges | McMaster-Carr

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	Pipe Size Pipe Size	Show

3/8

	Pipe Size Pipe Size	Hide

1/8
1/4
3/8
1/2
3/4
1
1 1/4
1 1/2
2
2 1/2
3
3 1/2
4
5
6
8
10
12

	Thread Type Thread Type

	Material Material

	Type Type


Locknut	Plug

	For Pipe Material For Pipe Material

	System of Measurement System of Measurement

Inch

Metric

	Shape Shape

	Straight
	Cap/Plug

	Connection Style Connection Style

Threaded

	Connection Type Connection Type

	Pipe

	Hex Width Hex Width

7/8"

63/64"

1 1/8"

	For Use With For Use With

	Finish Finish

Anodized

Galvanized

	Maximum Pressure Maximum Pressure

	Thread Size Thread Size

M16

	Length Length

	Gender Gender

Female

Male

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

RoHS Compliant

RoHS Compliant with
Exemptions

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

DFARS Specialty Metals
COTS-Exempt

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

REACH Compliant

	Specifications Met Specifications Met

	For Pipe Schedule For Pipe Schedule


40	XXH

	Pressure Class Pressure Class

125

150

	Maximum Steam Pressure Maximum Steam Pressure

150 psi @ 350° F

5,000 psi @ 500° F

Not Rated

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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.

How to Measure Threaded Pipe Size

Low-Pressure Stainless Steel Threaded Pipe Fittings

Use these fittings in a low-pressure pipe line.

Fittings that meet ANSI/MSS SP-114 adhere to high-quality standards for heat treating, material thickness, and marking. 304 stainless steel fittings have very good corrosion resistance. 316 stainless steel fittings have excellent corrosion resistance.

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

NPTF (Dryseal) threads and 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: Air, Natural Gas, Oil, Steam, Water
Pressure Class:
NPSL: 150
Fabrication:
NPSL: Heat Treated
Specifications Met:
NPSL: ANSI/MSS SP-114, ASTM A351
BSPP: DIN 431
Pipe Nipples and Pipe:
NPSL: Use Schedule 40 stainless steel
Flanges:
NPSL: Use Class 150 stainless steel

			304 Stainless Steel		316 Stainless Steel
Pipe Size	Max. Pressure	Max. Steam Pressure		Each		Each
NPSL Female
3/8	300 psi @ 72° F	150 psi @ 350° F	00000000	00000	00000000	00000

Low-Pressure Galvanized Iron and Steel Threaded Pipe Fittings

The galvanized finish on these fittings provides fair corrosion resistance. Fittings are for use in low-pressure applications.

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

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

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

Locknut

For Use With: Air, Steam, Oil, Water, Natural Gas
Pressure Class: 150
Specifications Met: ASME B16.14
Pipe Nipples and Pipe: Use Schedule 40 galvanized steel
Flanges: Use Class 150 galvanized steel

NPSL Female
Pipe Size	Material		Each
3/8	Galvanized Iron	00000000	00000

Extreme-Pressure Steel Threaded Pipe Fittings

The strongest steel fittings we offer, these can withstand extreme-pressure applications.

Galvanized and zinc-plated steel fittings have better corrosion resistance than plain steel fittings. PTFE-coated steel fittings have better corrosion resistance than galvanized and zinc-plated steel 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, Hydraulic Fluid, Natural Gas, Oil, Steam, Water
Temperature Range: -100° to 500° F
Pipe Nipples and Pipe: Use Schedule XXH steel
Flanges: Use Class 1500 steel

NPT Female
Pipe Size	Dash Size	Max. Pressure	Max. Steam Pressure	Material		Each
3/8	06	10,000 psi @ 72° F	5,000 psi @ 500° F	Galvanized Steel	0000000	000000

Low-Pressure Aluminum Threaded Pipe Fittings

In addition to being lightweight, these aluminum fittings offer good corrosion resistance. Use them in low-pressure flow applications. To prevent cracking, do not tighten more than a 1/4-turn past hand tight.

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

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

DIN 3852 fittings meet DIN standards for mating surface outer diameter. They have a Buna-N rubber gasket that resists grease, hydraulic oil, and motor oil—plus mild chemicals and water. The gasket stays in a groove undercut in the mating face, which prevents it from dropping out and from extruding when fittings are tightened. Black anodized and powder-coated fittings have a decorative matte black finish.

The contact surface on fittings with a flange extends beyond the external hex drive.

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

Locknuts

For Use With: Air, Oil, Water
Pressure Class: 150
Pipe Nipples and Pipe: Use Schedule 40 aluminum
Flanges: Use Class 125 aluminum

NPSL Female
Pipe Size	Max. Pressure		Each
3/8	150 psi @ 72° F	000000000	00000

Plugs with External Hex Drive and Flange

BSPP and Metric
Male Threads
with Gasket

For Use With: Air, Oil, Water
Specifications Met: DIN 3852
Pipe Nipples and Pipe: Use aluminum

						Black Anodized Aluminum Alloy		Aluminum Alloy
Pipe Size	Thread Size	Thread Pitch, mm	Drive Size	Plug Construction	Max. Pressure		Each		Each
BSPP Male
3/8	__	__	18 mm	Solid	Not Rated	000000	00	00000000	00000
Metric Male
3/8	M16	1.5	18 mm	Solid	Not Rated	00000000	000000	00000000	0000

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.

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
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	00000

Plastic Pipe Fittings for Gasoline

Use these plastic fittings to connect gasoline fuel lines to machines and equipment. They have excellent corrosion resistance as well as high strength and impact resistance. Apply a non-hardening, plastic-compatible sealant to the male threads to prevent leaks. Tape or sealants with PTFE are not recommended for plastic-to-plastic threaded connections. When making a threaded connection be careful not to overtighten the threads. To prevent cracks and leaks, finger tighten the fitting, then wrench-tighten one to two turns.

Plugs with fluoroelastomer gaskets, also known as Viton® fluoroelastomer gaskets, ensure a tight seal. They also resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol.

Warning: Never use plastic pipe fittings and pipe with compressed air or gas.

Sealants cannot be sold to Colorado, Connecticut, District of Columbia, Delaware, Illinois, Indiana, Massachusetts, Maryland, Maine, Michigan, New Hampshire, New Jersey, Northern Virginia, New York, Ohio, Pennsylvania, Rhode Island, or Utah due to local VOC (Volatile Organic Compounds) regulations.

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

Plugs with External Hex Drive, Male Threaded Pipe

For Use With: Gasoline
Temperature Range:
Gray Plugs: -40° to 190° F
White Plugs: 32° to 160° F
Black Plugs: -20° to 210° F

BSPP Threads
Pipe Size	Drive Size	Material	Color	Gasket Material	Max. Pressure	Features		Each
3/8	22 mm	Nylon Plastic	Black	Fluoroelastomer Rubber	Not Rated	Flange	0000000	00000