Steel, 1095, spheroidized, annealed, astm a684; heat treat at 1450-1550 deg. F., water quench, temper 750 deg. F. 30 min. To hardness specified; manganese phosphate, type m, or zinc phosphate, type z, per mil-p-16232, class 1; 5.620 in. Lg.; 0.552 in. W.; 0.410 in. Thk.