Downloaded from https://www.everyspec.com MIL-STO-131ZB D (NOTE 4) 1 COUNTERBORE (NOTE 5) r1 . 500 + L 1 - - 1 I f ‘!!II I T J L.250 . 7 I COUNTERBORE (NOTE 5) D’ (NOTE 4) @ r 1.500 + NEVER LESS THAN O.020 7 t- .500 DIA BALL \ -d L -41- .250 L,.500J NOTliS: 1. Naterial: Alloy steel. 2. Hea”ttreat: 48-50 HRC , ; 3. Ma~hine or grind edges square with face. 4. = (D + .001) +.004 -.000 where D equals the fastener maximum shank diameter. 5. Counterbore as required for grip. FIGURE 20. Test plate. 38