Specifications

Conform to Dimensions in mm
BS 328 Part 2 : 1990

TWIST DRILLS - Centre Drill(Inch Sizes)
B.S. No Body Diameter Pilot Diameter Max Pilot Diameter Min Pilot Length Length Overall Length Size Overall Length Tol±
1 1/8 3/64 5/64 1/16 1.1/2 1/32
2 3/16 1/16 3/32 5/64 1.3/4 1/32
3 1/4 3/32 5/32 1/8 2 1/16
4 5/16 1/8 3/16 5/32 2.1/4 1/16
5 7/16 3/16 9/32 1/4 2.1/2 3/32
6 5/8 1/4 3/8 5/16 3 3/32
7 3/4 5/16 15/32 13/32 3.1/2 3/32


Figures Mentioned in red are for reference only
Range Of Applications:- For producing center hole form A