How long are the threads on a 1" gas pipe?

For a 1" gas pipe, the standard length of threads is indeed 7/8". This length provides sufficient engagement for the connection while ensuring compatibility with fittings and other components typically used in gas piping systems. The 7/8" threading length is a standardized practice that promotes secure and leak-proof joints, which are essential for gas applications where safety and reliability are paramount. Using the correct thread length helps prevent issues such as insufficient joint strength or potential leaks, which can arise from using improperly threaded or overly long threads.

In contrast, the other options either exceed or fall short of this standardized length, which could compromise the integrity of the gas line installation. Hence, knowing the specific threading length is crucial for plumbing professionals to ensure safe and effective gas piping systems.