Welding Hose Nuts | McMaster-Carr

	For Use With For Use With

	Thread Size Thread Size

	Thread Type Thread Type

	Type Type


Nut	Adapter

Connector

	CGA Number CGA Number

020
021
022
023
024
025
026
027
030
031
032
033
034
035
170
180
200
280
296
300
320
326
330
346
347
350
410
500
510
520
540
555
577
580
590
660
670
677
680
701
702
705

	Gender Gender


Female	Male

	Material Material

Brass

Stainless Steel

	Thread Direction Thread Direction

Right Hand

Left Hand

	Connection Style Connection Style

Threaded

Barbed

	Maximum Pressure Maximum Pressure

	Length Length

	Tighten With Tighten With

Wrench

Hand

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

RoHS Compliant with
Exemptions

RoHS Compliant

	Minimum Temperature Minimum Temperature

-65° F

0° F

Not Rated

	Maximum Temperature Maximum Temperature

120° F

250° F

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

DFARS Specialty Metals
COTS-Exempt

	Finish Finish

Chrome Plated

Aluminum Plated

	Gas Fitting Size Gas Fitting Size

	For Hose ID For Hose ID

	Pipe Size Pipe Size

5/8

3/4

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

REACH Compliant

	DIN Number DIN Number

477 No. 6

477 No. 9

477 No. 12

	Number of Pieces Number of Pieces

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64 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. Aluminum-plated brass nuts have better corrosion and wear resistance than unplated brass. Chrome-plated brass nuts have comparable corrosion and wear resistance to aluminum-plated brass nuts, and have a bright, shiny appearance. 316 stainless steel nuts have excellent corrosion resistance.

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

Nuts with left-hand threads are identified with a notch.

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.

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

Female

Female Nut

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

Brass
Number	Thread Size	Pipe Size	Thread Type	Thread Direction	Max. Pressure	For Use With		Each
CGA 200	0.628"-20	__	NGO	Right Hand	500 psi @ 72° F	Acetylene	000000000	00000
CGA 280	0.750"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Medical Gas Mixtures	000000000	00000
CGA 300	0.830"-14	__	NGO	Right Hand	500 psi @ 72° F	Ethyl Chloride	000000000	0000
CGA 320	0.830"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Carbon Dioxide	000000000	0000
CGA 326	0.830"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Nitrous Oxide	000000000	0000
CGA 330	0.830"-14	__	NGO	Left Hand	3,000 psi @ 72° F	Boron Trifluoride, Carbonyl Sulfide, Hydrogen Bromide, Hydrogen Chloride, Hydrogen Iodide, Hydrogen Sulfide, Methyl Bromide, Silicon Tetrafluoride, Sulfur Tetrafluoride	000000000	00000
CGA 346	0.830"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Air	000000000	0000
CGA 347	0.830"-14	__	NGO	Right Hand	4,700 psi @ 72° F	Air	000000000	00000
CGA 350	0.830"-14	__	NGO	Left Hand	3,000 psi @ 72° F	Carbon Monoxide, Ethane, Ethylene, Hydrogen, Methane, Methyl Fluoride, Natural Gas	000000000	0000
CGA 410	0.855"-14	__	NGO	Left Hand	500 psi @ 72° F	Acetylene	000000000	0000
CGA 520	0.899"-14	__	NGO	Right Hand	500 psi @ 72° F	Acetylene	000000000	0000
CGA 540	0.908"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Oxygen	000000000	0000
CGA 555	0.908"-14	__	NGO	Left Hand	3,000 psi @ 72° F	Butane, LP Gas	000000000	0000
CGA 577	0.965"-14	__	NGO	Right Hand	3,500 psi @ 72° F	Oxygen	000000000	00000
CGA 660	1.035"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Refrigerant Gases	000000000	0000
CGA 701	1.108"-14	__	NGO	Right Hand	4,700 psi @ 72° F	Oxygen	000000000	00000
DIN 477 No. 9	__	3/4	BSPT	Right Hand	4,300 psi @ 72° F	Oxygen	000000000	00000
Brass with Plastic Grip
CGA 320	0.830"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Carbon Dioxide	000000000	00000
CGA 346	0.830"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Air	000000000	00000
CGA 540	0.908"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Oxygen	000000000	00000
Aluminum-Plated Brass
CGA 170	9/16"-18	__	UN/UNF (CGA)	Right Hand	3,000 psi @ 72° F	Air, Argon, Butane, Carbon Dioxide, Helium, Krypton, Methane, Natural Gas, Neon, Nitrogen, Oxygen, Propane, Propylene	000000000	0000
CGA 180	5/8"-18	__	UN/UNF (CGA)	Right Hand	3,000 psi @ 72° F	Air, Argon, Butane, Carbon Dioxide, Helium, Krypton, Methane, Natural Gas, Neon, Nitrogen, Oxygen, Propane, Propylene	000000000	00000
DIN 477 No. 6	W 21.8	__	Metric	Right Hand	3,000 psi @ 72° F	Argon, Carbon Dioxide, Cyclobutane, Dichlorotetrafluoroethane, Helium, Krypton, Sulfur Hexafluoride, Trifluoroethane, Xenon	000000000	00000
Chrome-Plated Brass
CGA 320	0.830"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Carbon Dioxide	000000000	00000
CGA 326	0.830"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Nitrous Oxide	00000000	00000
CGA 346	0.830"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Air	00000000	00000
CGA 350	0.830"-14	__	NGO	Left Hand	3,000 psi @ 72° F	Carbon Monoxide, Ethane, Ethylene, Hydrogen, Methane, Methyl Fluoride, Natural Gas	000000000	00000
CGA 540	0.908"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Oxygen	000000000	0000
316 Stainless Steel
CGA 670	1.035"-14	__	NGO	Left Hand	3,000 psi @ 72° F	Hydrogen Fluoride, Nitrogen Trifluoride, Tungsten Hexafluoride	000000000	00000
CGA 677	1.035"-14	__	NGO	Left Hand	6,400 psi @ 72° F	Argon, Helium, Krypton, Neon, Nitrogen, Xenon	000000000	00000
CGA 705	1.125"-14	__	UNS	Right Hand	3,000 psi @ 72° F	Ammonia	000000000	00000

Male

Male Nut

Maximum Pressure: See table
Maximum Temperature: 120° F, except DIN 477 No. 12: 250° F

Brass
Number	Thread Size	Pipe Size	Thread Type	Thread Direction	Max. Pressure	For Use With		Each
CGA 296	0.803"-14	__	UNS	Right Hand	3,000 psi @ 72° F	Oxygen Mixtures	000000000	00000
CGA 500	0.880"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Medical Gas Mixtures	000000000	00000
CGA 510	0.880"-14	__	NGO	Left Hand	500 psi @ 72° F	Acetylene, Butane, Cyclopropane, Dimethyl Ether, Ethylene Oxide, Isobutane, Methane, Methyl Chloride, Natural Gas, Propane, Propylene, Vinyl Bromide, Vinyl Chloride	000000000	0000
CGA 580	0.960"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Argon, Helium, Krypton, Neon, Nitrogen, Xenon	000000000	0000
CGA 590	0.960"-14	__	NGO	Left Hand	3,000 psi @ 72° F	Sulfur Hexafluoride	000000000	0000
CGA 680	1.040"-14	__	NGO	Right Hand	4,700 psi @ 72° F	Argon, Helium, Krypton, Neon, Nitrogen, Xenon	000000000	00000
CGA 702	1.120"-14	__	NGO	Right Hand	6,400 psi @ 72° F	Air	000000000	00000
DIN 477 No. 12	__	3/4	BSPT	Right Hand	4,300 psi @ 72° F	Nitrous Oxide	000000000	00000
Brass with Plastic Grip
CGA 500	0.880"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Medical Gas Mixtures	00000000	00000
CGA 510	0.880"-14	__	NGO	Left Hand	500 psi @ 72° F	Acetylene, Butane, Cyclopropane, Dimethyl Ether, Ethylene Oxide, Isobutane, Methane, Methyl Chloride, Natural Gas, Propane, Propylene, Vinyl Bromide, Vinyl Chloride	000000000	00000
CGA 580	0.960"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Argon, Helium, Krypton, Neon, Nitrogen, Xenon	000000000	00000
CGA 590	0.960"-14	__	UN/UNF (CGA)	Left Hand	3,000 psi @ 72° F	Sulfur Hexafluoride	00000000	00000
Aluminum-Plated Brass
BS 341 No. 3	__	5/8	BSPT	Right Hand	3,000 psi @ 72° F	Air, Argon, Helium, Krypton, Neon, Nitrogen, Oxygen, Perfluoropropane	000000000	00000
Chrome-Plated Brass
CGA 510	0.880"-14	__	NGO	Left Hand	500 psi @ 72° F	Acetylene, Butane, Cyclopropane, Dimethyl Ether, Ethylene Oxide, Isobutane, Methane, Methyl Chloride, Natural Gas, Propane, Propylene, Vinyl Bromide, Vinyl Chloride	000000000	00000
CGA 580	0.960"-14	__	NGO	Right Hand	3,000 psi @ 72° F	Argon, Helium, Krypton, Neon, Nitrogen, Xenon	000000000	00000
CGA 590	0.960"-14	__	NGO	Left Hand	3,000 psi @ 72° F	Sulfur Hexafluoride	000000000	00000

Nuts for Barbed Hose Fittings for Compressed Gas

Also known as CGA (Compressed Gas Association) nuts, these are designed for low-pressure welding applications downstream of your tank and pressure regulator. Slide a barbed hose adapter for compressed gas into a male or female nut to make a threaded connection to torches or pressure regulators.

Nuts with left-hand threads are identified with a notch.

Brass nuts have good corrosion resistance. Stainless steel nuts have excellent corrosion resistance.

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

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

Female

Maximum Pressure: 200 psi @ 72° F
Maximum Temperature: 120° F

Brass
CGA Number	Gas Fitting Size	Thread Size	Thread Type	Thread Direction	For Use With		Each
020	A	3/8"-24	UN/UNF (CGA)	Right Hand	Oxygen	0000000	00000
021	A	3/8"-24	UN/UNF (CGA)	Left Hand	Acetylene, Butane, Fuel Gases, LP Gas, Natural Gas, Propane	000000000	000
022	B	9/16"-18	UN/UNF (CGA)	Right Hand	Oxygen	000000	000
023	B	9/16"-18	UN/UNF (CGA)	Left Hand	Acetylene, Butane, Fuel Gases, LP Gas, Natural Gas, Propane	000000	000
024	C	7/8"-14	UN/UNF (CGA)	Right Hand	Oxygen	000000000	0000
025	C	7/8"-14	UN/UNF (CGA)	Left Hand	Acetylene, Butane, Fuel Gases, LP Gas, Natural Gas, Propane	000000000	0000
026	D	1 1/4"-12	UN/UNF (CGA)	Right Hand	Oxygen	000000000	00000
027	D	1 1/4"-12	UN/UNF (CGA)	Left Hand	Acetylene, Butane, Fuel Gases, LP Gas, Natural Gas, Propane	000000000	00000
316 Stainless Steel
022	B	9/16"-18	UN/UNF (CGA)	Right Hand	Oxygen	000000000	00000

Male

Maximum Pressure: 200 psi @ 72° F
Maximum Temperature: 120° F

Brass
CGA Number	Gas Fitting Size	Thread Size	Thread Type	Thread Direction	For Use With		Each
030	A	3/8"-24	UN/UNF (CGA)	Right Hand	Argon, Helium, Krypton, Neon, Nitrogen, Xenon	000000000	00000
031	A	3/8"-24	UN/UNF (CGA)	Left Hand	Air, Water	000000000	0000
032	B	5/8"-18	UN/UNF (CGA)	Right Hand	Argon, Helium, Krypton, Neon, Nitrogen, Xenon	0000000	0000
033	B	5/8"-18	UN/UNF (CGA)	Left Hand	Air, Water	0000000	0000
034	C	7/8"-14	UN/UNF (CGA)	Right Hand	Argon, Helium, Krypton, Neon, Nitrogen, Xenon	000000000	0000
035	C	7/8"-14	UN/UNF (CGA)	Left Hand	Air, Water	000000000	0000

Hose Crimping Tool and Fitting Sets for Compressed Gas

Sets contain a crimping tool and a variety of fittings, nuts, and ferrules so you can connect pressure regulators, torches, and other components of your welding system. Fittings are also known as CGA (Compressed Gas Association) fittings. They are brass for good corrosion resistance.

Barbed adapters let you adapt to a threaded end so you can connect welding hose to pressure regulators or torches. They consist of a barbed shaft with a rounded end that sits inside a threaded nut so you can make a threaded hose connection.

Barbed connectors are also known as hose menders and splicers. Use them to connect lengths of hose or to repair damaged hose. Slide the barbed end into welding hose and use a hose ferrule and the crimping tool to secure the fitting to hose.

Threaded connectors let you attach threaded welding hose to pressure regulators and torches.

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.

Brass
For Hose ID	No. of Pieces	Includes	Max. Pressure	For Use With		Each
3/16", 1/4"	93	Crimping Tool Eight barbed hose adapters for 3/16" hose ID (use with A-size nuts) Six barbed hose adapters for 3/16" hose ID (use with B-size nuts) Ten barbed hose adapters for 1/4" hose ID (use with B-size nuts) Two barbed hose connectors for 3/16" hose ID Four barbed hose connectors for 1/4" hose ID One A-size 3/8"-24 male right-hand threaded connector (CGA-020) One A-size 3/8"-24 male left-hand threaded connector (CGA-021) One B-size 9/16"-18 male right-hand threaded connector (CGA-022) One B-size 9/16"-18 male left-hand threaded connector (CGA-023) Four A-size 3/8"-24 right-hand threaded nuts (CGA-020) Four A-size 3/8"-24 left-hand threaded nuts (CGA-021) Eight B-size 9/16"-18 female right-hand threaded nuts (CGA-022) Eight B-size 9/16"-18 female left-hand threaded nuts (CGA-023) Twelve ferrules with 0.45" hose end ID Ten ferrules with 0.562" hose end ID Twelve ferrules with 0.593" hose end ID	200 psi @ 72° F	Acetylene, Butane, Fuel Gases, LP Gas, Natural Gas, Oxygen, Propane	0000000	0000000
5/16", 3/8"	71	Crimping Tool Eight barbed hose adapters for 5/16" hose ID (use with B-size nuts) Eight barbed hose adapters for 3/8" hose ID (use with B-size nuts) Two barbed hose connectors for 5/16" hose ID Two barbed hose connectors for 3/8" hose ID One B-size 9/16"-18 male right-hand threaded connector (CGA-022) One B-size 9/16"-18 male left-hand threaded connector (CGA-023) Eight B-size 9/16"-18 female right-hand threaded nuts (CGA-022) Eight B-size 9/16"-18 female left-hand threaded nuts (CGA-023) Eight ferrules with 0.625" hose end ID Eight ferrules with 0.656" hose end ID Six ferrules with 0.687" hose end ID Eight ferrules with 0.718" hose end ID	200 psi @ 72° F	Acetylene, Butane, Fuel Gases, LP Gas, Natural Gas, Oxygen, Propane	0000000	000000