Identifies bolts, fittings, pipe threads and spark plugs with US or metric threads
Aluminum gauges identify: 1) US threads from #5 to 3/4" and pitch of 10TPI to 44TPI; 2) Metric threads from 2.5 to 22mm and pitch of .45 to 2.5mm; 3) Pipe threads 1/16" to 1/2" with 14TPI to 27TPI; and 4) Spark plug threads 10 to 18mm.