Version: Assembly of holders, countersinks, and guide pins for processing the most common drilling diameters. Note: Combination countersink sets are also available in HSS with optional TIN coating, as well as with soldered carbide cutting edges and with ISO indexable inserts type "T" upon request. Use: For DIN countersinks and, with the appropriate pin/countersink combination, for stepped drilling or countersinking outside of the standard.