Parlec C50-60TT5C Tapping Heads; Shank Type: Taper Shank; Shank Diameter (Inch): 1; Taper Size: CAT50; Minimum Tap Capacity (mm): M20; Minimum Tap Capacity (Inch): 3/4; Maximum Aluminum Tap Capacity (mm): M90; Maximum Aluminum Tap Capacity (Inch): 9/