This plug gauge is a standard tool for testing NPT threads.
Package included: AS your choosed
1* Taper Pipe Plug Thread Gage
The plug gauge has 3 step marks Rotate this plug gauge into the inspected thread. when Thread to “下” this thread Size Small Unqualified threads when Thread to “基” this thread Size Standard Qualified threads when Thread to “上” this thread Size Large Unqualified threads