Countersunk Square Holes for Cutting Edges and End Bits
To be used on cutting edges and end bits in conjunction with No. 3 head plow bolts (Ref. ANSI B18.9) typically used on off-road self-propelled work machines as described in SAE J1116. Cutting edges are further defined in SAE J737, J739 and J1304. End bits are further defined in SAE J63. 1 When section thickness exceeds A in drawing 1 (Figure 2) (countersunk one side) or B in drawing 4 (countersunk both sides), use counterbore with diameter D, as shown in cross section drawings 2, 5 and 6, or extended countersink C, as shown in cross section drawings 3 and 7. 2 The inscribed circle of the square holes shall be concentric with countersink or counterbore within 0.03 in (0.8 mm).