IDP
Exchangeable Drilling Bits with Coolant Holes, for Carbon and Alloy Steel (ISO P)

IDN
Exchangeable Drilling Bits with Coolant Holes, for Aluminum (ISO N)

IDK
Exchangeable Drilling Bits with Coolant Holes, for Cast Iron (ISO K)

IDM
Exchangeable Drilling Bits with Coolant Holes, for Stainless Steel and High Temperature Alloys (ISO M)