This tank cutter has a straight shank with 3 flats upon it to ensure a positive drive when used in 3 jaw chuck. This tank cutter is suitable for use in a hand held brace or drill stand. The cutting blade is manufactured from heat-treated high speed steel and the cutter has a high speed steel pilot drill and is suitable for use on most tank materials. Capacity 25 - 125mm (1-5 in) . Shank. Straight. Cutter. H.S.S. "