Please use the following table as an outline for bolt hole drill size.

Twist BoltsDrill Hole Dia.Min. Drill Hole Depth
6mmx80mm1/2”3-1/2″
6mmx100mm1/2″100 mm or 4″
6mmx150mm1/2″160 mm or 6″
8mmx100mm18 mm100 mm or 4″
8mmx150mm18 mm160mm or 6″
Solid Leg Bolt, (SLB’s)
8 mm x 80 mm10 mm90 mm or 3-1/2″
8 mm x 100 mm10 mm100 mm or 4"
10 mm x 80 mm12 mm90 mm or 3-1/2″
10 mm x 100 mm12 mm100 mm or 4″
10 mm x 150 mm12 mm160mm or 6″
12 mm x 100 mm14 mm100 mm or 4″
12 mm x 150 mm14 mm160 mm or 6″
Wedge Bolts
10 mm x 80 mm10mm90 mm or 3-1/2″
10 mm x 100mm10mm100 mm or 4″