2a single mounting facility thread class 1.010" 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 0.410" single mounting facility thread length 1.897" overall length tap, circular, bushing mount unf single mounting facility thread series
2b single mounting facility thread class 0.480" overall length 1.610" overall width 56 single mounting facility thread quantity per inch rectangular indicating unc single mounting facility thread series