CGA 346 Fittings | McMaster-Carr

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100° F to 249° F

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9 Products

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.

Nuts for High-Pressure Nipples for Compressed Gas

Slide a high-pressure hose nipple for compressed gas into one of these nuts to connect a pipe to the inlet of a pressure regulator. They are also known as CGA (Compressed Gas Association) nuts and inlet nuts.

Brass nuts have good corrosion resistance and are softer than 316 stainless steel nuts, so they're easier to thread together. Chrome-plated brass nuts have comparable corrosion and wear resistance to aluminum-plated brass nuts, and have a bright, shiny appearance.

Nuts with a plastic grip can be tightened by hand instead of with a wrench.

Note: Nuts have a CGA, BS, or DIN number that corresponds to a specific type of gas. Choose a nut with the same number as your tank and other system components.

Female

Female Nut

Maximum Pressure: See table
Maximum Temperature: 120° F, except DIN 477 No. 9: 250° F

Brass
Number	Thread Size	Thread Type	Thread Direction	Max. Pressure	For Use With		Each
CGA 346	0.830"-14	NGO	Right Hand	3,000 psi @ 72° F	Air	000000000	00000
Brass with Plastic Grip
CGA 346	0.830"-14	NGO	Right Hand	3,000 psi @ 72° F	Air	000000000	00000
Chrome-Plated Brass
CGA 346	0.830"-14	NGO	Right Hand	3,000 psi @ 72° F	Air	00000000	00000

High-Pressure Nipples for Compressed Gas

Commonly used in high-pressure welding applications, these nipples connect your tank to the inlet of a pressure regulator. One side has a threaded pipe end and the other side has a rounded end that sits inside a threaded nut (sold separately) so you can make a threaded connection.

Brass nipples have good corrosion resistance and are softer than 316 stainless steel nipples, so they're easier to thread together. Chrome-plated brass nipples have better corrosion and wear resistance than unplated brass nipples and have a bright, shiny appearance.

Nipples, Tank × Male Regulator

Maximum Pressure: See table
Maximum Temperature: 120° F

	Regulator Connection
For Number (Max. Pressure)	Pipe Size	Thread Type	Lg.	For Use With		Each
Brass—Tighten With Wrench
CGA 346 (3,000 psi @ 72° F)	1/4	NPT	2 1/2"	Air	000000000	00000
Chrome-Plated Brass—Tighten With Wrench
CGA 346 (3,000 psi @ 72° F)	1/4	NPT	2 1/2"	Air	0000000	00000

Nuts

Female Nut

Maximum Pressure: See table
Maximum Temperature: 120° F

Brass
Number	Gender	Thread Size	Thread Type	Thread Direction	Max. Pressure	For Use With		Each
CGA 346	Female	0.830"-14	NGO	Right Hand	3,000 psi @ 72° F	Air	000000000	00000
Chrome-Plated Brass
CGA 346	Female	0.830"-14	NGO	Right Hand	3,000 psi @ 72° F	Air	00000000	00000

High-Pressure Threaded Fittings for Compressed Gas

Designed to handle high-pressure welding applications, these fittings are commonly used to connect pressure regulators to compressed gas tanks or cylinders. Fittings are also known as CGA (Compressed Gas Association) fittings. They are brass for good corrosion resistance.

Fittings with left-hand threads are identified with a notch in the nut.

Note: Fittings have a CGA number that corresponds to a specific type of gas. Choose a fitting with the same CGA number as your tank and other system components.

Female Tank × Female Regulator

Maximum Pressure: See table
Maximum Temperature: 120° F

CGA Number		Tank Connection			Regulator Connection
Tank	Regulator	Thread Size	Thread Type	Thread Direction	Thread Size	Thread Type	Thread Direction	Max. Pressure	For Use With		Each
Brass
346	580	0.830"-14	NGO	Right Hand	0.960"-14	NGO	Right Hand	3,000 psi @ 72° F	Air, Argon, Helium, Krypton, Neon, Nitrogen, Xenon	0000000	000000

Female Tank × Male Regulator

Maximum Pressure: See table
Maximum Temperature: 120° F

CGA Number		Tank Connection			Regulator Connection
Tank	Regulator	Thread Size	Thread Type	Thread Direction	Thread Size	Thread Type	Thread Direction	Max. Pressure	For Use With		Each
Brass
346	540	0.830"-14	NGO	Right Hand	0.908"-14	NGO	Right Hand	3,000 psi @ 72° F	Air, Oxygen	0000000	000000

Male Tank × Male Regulator

Maximum Pressure: See table
Maximum Temperature: 120° F

CGA Number		Tank Connection			Regulator Connection
Tank	Regulator	Thread Size	Thread Type	Thread Direction	Thread Size	Thread Type	Thread Direction	Max. Pressure	For Use With		Each
Brass
580	346	0.960"-14	NGO	Right Hand	0.825"-14	NGO	Right Hand	3,000 psi @ 72° F	Air, Argon, Helium, Krypton, Neon, Nitrogen, Xenon	0000000	000000
590	346	0.960"-14	NGO	Left Hand	0.830"-14	NGO	Right Hand	3,000 psi @ 72° F	Air, Sulfur Hexafluoride	0000000	00000