2b thread class right-hand 24 thread quantity per inch 4 holes eq spaced 0.250 in dia, 2 holes 0.138 in dia 32unc-2b, NSN1015-00-840-1840, mortar 4.2-inch
0.266" hole diameter 1.365" outside diameter 0.235" material thickness 1 hole drilled 0.147 p 0.010 dia on ctr line 0.437r orm 0.005 c to c 15 recessed