Countersunk Square Holes for Cutting Edges and End Bits(STABILIZED Oct 2011)
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.