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

- 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 660 (3,000 psi @ 72° F) | 1/4 | NPT | 1 3/4" | Refrigerant Gases | 000000000 | 000000 |

- Maximum Pressure: See table
- Maximum Temperature: 120° F
Number | Gender | Thread Size | Thread Type | Thread Direction | Max. Pressure | For Use With | Each | |
Brass | ||||||||
---|---|---|---|---|---|---|---|---|
CGA 660 | Female | 1.035"-14 | NGO | Right Hand | 3,000 psi @ 72° F | Refrigerant Gases | 000000000 | 000000 |
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.
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.

- Maximum Pressure: See table
- Maximum Temperature: 120° F, except DIN 477 No. 9: 250° F
Number | Thread Size | Thread Type | Thread Direction | Max. Pressure | For Use With | Each | |
Brass | |||||||
---|---|---|---|---|---|---|---|
CGA 660 | 1.035"-14 | NGO | Right Hand | 3,000 psi @ 72° F | Refrigerant Gases | 000000000 | 000000 |
45° Flared Fittings for Copper and Brass Tubing

- Temperature Range: -65° to 250° F
- Tubing: Use with seamless brass and copper that meets ASTM B280
No sleeve is required to assemble these fittings, which makes for a faster, more convenient installation compared to 37° flared fittings. They require a nut (sold separately) for each tube end. Fittings are also known as refrigeration and SAE fittings. They are brass for good corrosion resistance.
NPTF (Dryseal) threads are compatible with NPT threads.
Copper tube size is the accepted designation of the copper tubing industry, not the actual tube OD.
For technical drawings and 3-D models, click on a part number.

- For Use With: Air, Cutting Oil, Diesel Fuel, Fuel Oil, Mineral Oil, Refrigerant, Water; except adapters for 1/8" and 1" tube OD are not for use with fuel oil
- Specifications Met: See table
For Tube | |||||||
---|---|---|---|---|---|---|---|
OD | Wall Thick. | Pipe Size | Material | Max. Pressure | Specifications Met | Each | |
NPTF Threads | |||||||
3/16" | 0.03" | 1/8 | Brass | 1,900 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 00000 |
3/16" | 0.03" | 1/4 | Brass | 1,900 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 00000 |
1/4" | 0.03" | 1/8 | Brass | 1,400 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
1/4" | 0.03" | 1/4 | Brass | 1,400 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
1/4" | 0.03" | 3/8 | Brass | 1,400 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
1/4" | 0.03" | 1/2 | Brass | 1,400 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 00000 |
5/16" | 0.032" | 1/8 | Brass | 1,200 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
5/16" | 0.032" | 1/4 | Brass | 1,200 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
3/8" | 0.032" | 1/8 | Brass | 1,000 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
3/8" | 0.032" | 1/4 | Brass | 1,000 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
3/8" | 0.032" | 3/8 | Brass | 1,000 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
3/8" | 0.032" | 1/2 | Brass | 1,000 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
3/8" | 0.032" | 3/4 | Brass | 1,000 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 00000 |
1/2" | 0.032" | 1/4 | Brass | 750 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
1/2" | 0.032" | 3/8 | Brass | 750 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
1/2" | 0.032" | 1/2 | Brass | 750 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 0000 |
1/2" | 0.032" | 3/4 | Brass | 750 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 00000 |
5/8" | 0.035" | 1/4 | Brass | 650 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 00000 |
5/8" | 0.035" | 3/8 | Brass | 650 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 00000 |
5/8" | 0.035" | 1/2 | Brass | 650 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 00000 |
5/8" | 0.035" | 3/4 | Brass | 650 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 00000 |
3/4" | 0.035" | 1/2 | Brass | 550 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 00000 |
3/4" | 0.035" | 3/4 | Brass | 550 psi @ 72° F | SAE J512, SAE J513, UL Listed | 000000000 | 00000 |



- For Use With: Air, Cutting Oil, Diesel Fuel, Fuel Oil, Mineral Oil, Refrigerant, Water; except nuts for 1" tube OD are not for use with fuel oil
- Specifications Met: SAE J512, SAE J513, UL Listed; except nuts for 1" tube OD meet SAE J512 and SAE J513 only
For Tube | |||||||
---|---|---|---|---|---|---|---|
OD | Wall Thick. | Nut Material | Max. Pressure | Lg. | Each | ||
Short Nuts | |||||||
A | 3/16" | 0.035" | Brass | 1,900 psi @ 72° F | 5/8" | 000000000 | 00000 |
A | 1/4" | 0.049" | Brass | 1,400 psi @ 72° F | 3/4" | 000000000 | 0000 |
A | 5/16" | 0.049" | Brass | 1,200 psi @ 72° F | 7/8" | 000000000 | 0000 |
A | 3/8" | 0.032" | Brass | 1,000 psi @ 72° F | 29/32" | 000000000 | 0000 |
A | 3/8" | 0.065" | Brass | 1,000 psi @ 72° F | 1" | 000000000 | 0000 |
A | 1/2" | 0.032" | Brass | 750 psi @ 72° F | 1" | 000000000 | 0000 |
A | 1/2" | 0.083" | Brass | 750 psi @ 72° F | 1 1/8" | 000000000 | 0000 |
A | 5/8" | 0.035" | Brass | 650 psi @ 72° F | 1 1/16" | 000000000 | 00000 |
A | 5/8" | 0.095" | Brass | 650 psi @ 72° F | 1 5/16" | 000000000 | 00000 |
A | 3/4" | 0.035" | Brass | 550 psi @ 72° F | 1 5/32" | 000000000 | 00000 |
A | 3/4" | 0.109" | Brass | 550 psi @ 72° F | 1 1/2" | 000000000 | 00000 |
B | 1/4" | 0.03" | Brass | 1,400 psi @ 72° F | 5/8" | 00000000 | 0000 |
B | 1/2" | 0.032" | Brass | 750 psi @ 72° F | 27/32" | 000000000 | 0000 |
B | 5/8" | 0.035" | Brass | 650 psi @ 72° F | 31/32" | 000000000 | 00000 |
Long Nuts | |||||||
A | 3/16" | 0.035" | Brass | 1,900 psi @ 72° F | 13/16" | 000000000 | 0000 |
A | 1/4" | 0.049" | Brass | 1,400 psi @ 72° F | 15/16" | 000000000 | 0000 |
A | 5/16" | 0.049" | Brass | 1,200 psi @ 72° F | 1 1/8" | 000000000 | 0000 |
A | 3/8" | 0.065" | Brass | 1,000 psi @ 72° F | 1 5/16" | 000000000 | 0000 |
A | 1/2" | 0.083" | Brass | 750 psi @ 72° F | 1 5/8" | 000000000 | 00000 |
A | 5/8" | 0.095" | Brass | 650 psi @ 72° F | 1 7/8" | 000000000 | 00000 |
A | 3/4" | 0.109" | Brass | 550 psi @ 72° F | 2 3/16" | 000000000 | 00000 |
Supported 45° Flared Fittings for Copper and Brass Tubing


- For Use With: Air, Cutting Oil, Diesel Fuel, Fuel Oil, Mineral Oil, Refrigerant, Water
- Temperature Range: -65° to 250° F
- Tubing: Use with seamless brass and copper
- Specifications Met:
Metric: SAE J512, SAE J513, UL Listed
All other fittings: SAE J512, UL Listed; except tee connectors for 1/2" tube OD
The flared end nests inside the fitting body, providing extra support to the tubing. Fittings are also known as inverted 45° flared fittings, refrigeration fittings, and SAE fittings. To assemble, place the nut (sold separately) on the tubing, flare the end of the tubing, then insert the tubing into the fitting and tighten the nut. Fittings are brass for good corrosion resistance.
For technical drawings and 3-D models, click on a part number.