"STEEL MIL-S-5000 COMP 4340 COND F,SURFACE TREATMENT,ZINC CHROMATE PRIMER MIL-P-6808,CADMIUM-PLATED QQ-P-416 CLASS 2,TYPE 1,DIM.,5.875 IN. NOM LG,0.588 IN. NOM WIDTH,0.580 IN. NOM HEIGHT,TWO HOLES TAPPED INTO WIDTH 0.250-28 UNF CLASS 3B THREADS W/0.350 IN. MINDEPTH,HOLES LOCATED 1.337 IN. FROM EACH END W/3.200 IN. C TO C DISTANCE,ITEMSTENCILED WITH BLACK PAINT FWD ROTOR BOTTOM,ITEM USED ON ROTARY WING HEAD"