IS 12690 : 1989 Small Tools - Subland Twist Drills With Morse Taper Shank for Clearance Holes and Counterbores for Slotted Cheese Head Screws - Specification

1 Scope

1.1 This standard covers dimensions and other requirements forthe subland twist drills with morse taper shanks for producingclearance holes and counterbores for slotted cheese head screws ofM5 to M20 - Medium series conforming to IS 3406 : Part 2 : 1986`Dimensions for countersinks and counterbores : Part 2 Counterbores(second revision).

2 References

IS 1715 :1986Dimensions for self holding tapers

IS 3406 : Part 2 :1986 Dimensions for counterbores :Part 2 Counterbores

IS 5099 :1983Technical supply conditions for twist drills

IS 7778 :1975Methods for sampling small tools

IS 10915 :1984Terms, definitions and types of twist drills