"STEEL MIL-S-5626,HEAT TREAT 34 TO 39 ROCKWELL C HARDNESS RATING,250 UIN. MACHINED SURFACE FINISH,DISK SHAPE,3.375-16 UN-3A THD OD,0.750 IN. LG,0.687 P 0.001 IN. ID ORIFICE,100 UIN. MACHINED SURFACE FINISH,ORIFICE,1ST END FLUSH,2ND 3.120 IN. ID BY 0.294 P 0.027 IN. DP COUNTER BORE AND 0.312 IN. W BY 0.20 IN. DP WRENCHING SLOTS LOCATED 180 DEG APART"