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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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. 316 stainless steel nuts have excellent corrosion resistance.
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 | |
316 Stainless Steel | |||||||
---|---|---|---|---|---|---|---|
CGA 705 | 1.125"-14 | UNS | Right Hand | 3,000 psi @ 72° F | Ammonia | 000000000 | 000000 |

- Maximum Pressure: See table
- Maximum Temperature: 120° F, except DIN 477 No. 12: 250° F
Number | Thread Size | Thread Type | Thread Direction | Max. Pressure | For Use With | Each | |
Brass | |||||||
---|---|---|---|---|---|---|---|
CGA 296 | 0.803"-14 | UNS | Right Hand | 3,000 psi @ 72° F | Oxygen Mixtures | 000000000 | 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.
For technical drawings and 3-D models, click on a part number.

- Maximum Pressure: 3,000 psi @ 72° F
- Maximum Temperature: 120° F
CGA Number | Tank Connection | Regulator Connection | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
Tank | Regulator | Thread Size | Thread Type | Thread Direction | Thread Size | Thread Type | Thread Direction | For Use With | Each | |
Brass | ||||||||||
296 | 590 | 0.803"-14 | UNS | Right Hand | 0.960"-14 | NGO | Left Hand | Oxygen Mixtures, Sulfur Hexafluoride | 0000000 | 000000 |
Threaded Round Plugs for 37° Flared Tube

Designed to fit into 37° flared connections such as those found on JIC and SAE fittings, these plugs protect internally threaded connections from contaminants during fabrication and storage. Install them manually.
Polyethylene plugs resist chemicals better than aluminum plugs.
For technical drawings and 3-D models, click on a part number.