2b all threaded hole thread class 1.656" overall width 20 single pressure connection thread quantity per inch rectangular npt single pressure connection thread series
2a single mounting facility thread class 0.250" single mounting facility thread length 1.637" overall length 1.125" overall width circular wafer, bushing mount unef single mounting facility thread series
2a single mounting facility thread class 0.375" single mounting facility thread length 1.920" overall length 1.490" overall width circular wafer, bushing mount unef single mounting facility thread series