How to Identify and Measure Fittings
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Low-Temperature/High-Pressure D.O.T. Push-to-Connect Tube Fittings for Air

- Temperature Range: -40° to 200° F
- Tubing: Use with hard (Durometer 65D) nylon plastic
- Specifications Met:
Cartridges: D.O.T. FMVSS 571, SAE J2494-4, SAE J1131
All other fittings: D.O.T. FMVSS 571
Connect high-pressure brake lines with fittings that won’t crack in frigid temperatures. Often used on commercial trucks and trailers, these fittings meet Department of Transportation FMVSS 571 safety standards. Also known as instant fittings, they connect to tubing with a simple push, and an internal gripping ring and O-ring will hold the tubing tight. A built-in tube support slips inside the tubing to prevent it from collapsing. To disconnect, push on the release ring and pull the tubing out of the fitting. All have good corrosion resistance.
For technical drawings and 3-D models, click on a part number.


Straight cartridge fittings create a push-to-connect junction between equipment and tubing in your system. They’re designed to be used in unthreaded 6061 aluminum ports. If you want to use them in a different material, you may need to adjust the hole size for optimum performance. To install them, create a hole in your surface and push the fitting’s components into place before inserting the tubing until it’s flush against the tube stop.
Required Hole | ||||||||
---|---|---|---|---|---|---|---|---|
For Tube OD | Material | Max. Pressure | Dia. | Dp. | Hole Dia. Tolerance | Min. Plate Thick. | Each | |
1/4" | Brass | 250 psi @ 72° F | 0.504" | 0.5" | -0.002" to 0.002" | 0.5" | 00000000 | 000000 |
1/4" | Brass | 250 psi @ 72° F | 0.775" | 0.78" | -0.002" to 0.002" | 0.78" | 00000000 | 00000 |
3/8" | Brass | 250 psi @ 72° F | 0.65" | 0.65" | -0.002" to 0.002" | 0.65" | 00000000 | 00000 |
3/8" | Brass | 250 psi @ 72° F | 0.775" | 0.78" | -0.002" to 0.002" | 0.78" | 00000000 | 00000 |
1/2" | Brass | 250 psi @ 72° F | 0.775" | 0.78" | -0.002" to 0.002" | 0.78" | 00000000 | 00000 |
Low-Temperature D.O.T. Push-to-Connect Tube Fittings for Air

- Temperature Range: -40° to 210° F
- Tubing: Use with hard (Durometer 65D) nylon plastic
- Specifications Met: D.O.T. FMVSS 571, SAE J1131, SAE J2494-1, SAE J2494-3
except Identification Rings: D.O.T. FMVSS 571
Connect air brake lines with fittings that won’t crack in sub-zero temperatures. They meet Department of Transportation FMVSS 571 safety standards, so they’re often used in commercial trucks and trailers. Also known as instant fittings, they connect to tubing with a push, and an internal gripping ring and O-ring hold the tubing tight. Fittings have a built-in tube support that slips inside the tubing to prevent it from collapsing. To disconnect, push on the release ring and pull the tubing out of the fitting. They have good corrosion resistance. Use them at up to 150 psi and attach them to hard tubing.
NPTF (Dryseal) threads are compatible with NPT threads. The male threads have an acrylic sealant applied to protect against leaks.
For technical drawings and 3-D models, click on a part number.

For Tube OD | Pipe Size | Thread Size | Material | Max. Pressure | Features | Each | |
NPTF Threads | |||||||
---|---|---|---|---|---|---|---|
5/32" | 1/8 | __ | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |
1/4" | 1/8 | __ | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 0000 |
1/4" | 1/4 | __ | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 0000 |
3/8" | 1/4 | __ | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 0000 |
3/8" | 3/8 | __ | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 0000 |
1/2" | 3/8 | __ | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |
1/2" | 1/2 | __ | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
3/4" | 3/4 | __ | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |
6mm | 1/8 | __ | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 0000 |
6mm | 1/4 | __ | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 0000 |
8mm | 3/8 | __ | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 0000 |
Metric Threads | |||||||
6mm | __ | M12 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |
8mm | __ | M12 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |
10mm | __ | M12 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |
12mm | __ | M16 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |

For Tube OD | Material | Max. Pressure | Each | |
5/32" | Brass | 150 psi @ 72° F | 000000000 | 00000 |
1/4" | Brass | 150 psi @ 72° F | 00000000 | 0000 |
3/8" | Brass | 150 psi @ 72° F | 00000000 | 00000 |
1/2" | Brass | 150 psi @ 72° F | 00000000 | 00000 |
3/4" | Brass | 150 psi @ 72° F | 000000000 | 00000 |
4mm | Brass | 150 psi @ 72° F | 000000000 | 0000 |
6mm | Brass | 150 psi @ 72° F | 000000000 | 00000 |
8mm | Brass | 150 psi @ 72° F | 000000000 | 00000 |
10mm | Brass | 150 psi @ 72° F | 000000000 | 00000 |
12mm | Brass | 150 psi @ 72° F | 000000000 | 00000 |

Fittings with intermittent swivel rotate 360° before and after installation as needed to allow movement in the system and to prevent kinking.
For Tube OD | Pipe Size | Material | Max. Pressure | Features | Each | |
NPTF Threads | ||||||
---|---|---|---|---|---|---|
5/32" | 1/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |
1/4" | 1/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 0000 |
1/4" | 1/4 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 0000 |
3/8" | 1/4 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
3/8" | 3/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
1/2" | 3/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |
1/2" | 1/2 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
3/4" | 3/4 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |

Fittings with intermittent swivel rotate 360° before and after installation as needed to allow movement in the system and to prevent kinking.
For Tube OD | Pipe Size | Material | Max. Pressure | Features | Each | |
NPTF Threads | ||||||
---|---|---|---|---|---|---|
1/4" | 1/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 000000 |
1/4" | 1/4 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 0000 |
3/8" | 1/4 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
3/8" | 3/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
1/2" | 3/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
1/2" | 1/2 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |

Fittings with intermittent swivel rotate 360° before and after installation as needed to allow movement in the system and to prevent kinking.
Inline tees are also known as branch tees.
For Tube OD | Pipe Size | Material | Max. Pressure | Features | Each | |
NPTF Threads | ||||||
---|---|---|---|---|---|---|
1/4" | 1/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 000000 |
1/4" | 1/4 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
3/8" | 1/4 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
3/8" | 3/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
1/2" | 3/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
1/2" | 1/2 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |

Fittings with intermittent swivel rotate 360° before and after installation as needed to allow movement in the system and to prevent kinking.
Right-angle tees are also known as run tees.
For Tube OD | Pipe Size | Material | Max. Pressure | Features | Each | |
NPTF Threads | ||||||
---|---|---|---|---|---|---|
1/4" | 1/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 000000 |
1/4" | 1/4 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
3/8" | 1/4 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
3/8" | 3/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
1/2" | 3/8 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 00000000 | 00000 |
1/2" | 1/2 | Brass | 150 psi @ 72° F | Acrylic Thread Sealant | 000000000 | 00000 |

For Tube OD | Material | Max. Pressure | Each | |
1/4" | Brass | 150 psi @ 72° F | 00000000 | 000000 |
3/8" | Brass | 150 psi @ 72° F | 00000000 | 00000 |
1/2" | Brass | 150 psi @ 72° F | 00000000 | 00000 |
3/4" | Brass | 150 psi @ 72° F | 000000000 | 00000 |
6mm | Brass | 150 psi @ 72° F | 000000000 | 00000 |
8mm | Brass | 150 psi @ 72° F | 000000000 | 00000 |
10mm | Brass | 150 psi @ 72° F | 000000000 | 00000 |
12mm | Brass | 150 psi @ 72° F | 000000000 | 00000 |

Color-code your lines by snapping one of these rings over the release ring on low-temperature D.O.T. push-to-connect tube fittings. Often used in air brake lines for commercial trucks and trailers, they meet Department of Transportation FMVSS 571 safety standards.