2a single mounting facility thread class right-hand single mounting facility 1.375" overall length 0.735" overall width 48 single mounting facility thread quantity per inch unc single mounting facility thread series
2a single mounting facility thread class 0.437" single mounting facility thread length 1.899" overall length tap, circular, bushing mount unef single mounting facility thread series
2b all threaded hole thread class 2.750" overall length 2.875" overall width 32 all threaded hole thread quantity per inch rectangular unc all threaded hole thread series