"MATL L3C; 1.65625 IN. O/A LG; HEAD 1ST STEP 0.15625 IN. LG; HEAD 2ND STEP 0.09375 IN. LG,RECESSED 0.025 PORM 0.020 W/ 0.015 TO 0.025 R IN CORNER OF GROOVE; HEAD 3RD STEP 0.59375 IN. LG; SHANK 0.8125 IN. LG W/ 0.0625 R; HEAD W 0.2490 PORM 0.2425 IN. W/ 0.0625 IN. HOLE 0.078125 IN. DP; 1/4-28 UNF-2A THD P.D. .2258/.2225"