SAE J 2494-1
This SAE Standard covers general and dimensional specifications for brass bodied reusable Push-to-Connect tube fittings for use in the piping of vehicular air brake systems. This type of fitting is intended for use with nylon tubing per SAE J844. See SAE J2494-3 for the Performance Requirements of Reusable (Push-to-Connect) Fittings Intended for Use in Automotive Air Brake Systems and U.S. Department of Transportation, National Highway Traffic Safety Administration (NHTSA) Federal Motor Vehicle Safety Standards (FMVSS) 571.