Each high carbon steel tap and die has size and starting side permanently marked on each. All taps are plug style and have recommended drill size laser marked on the side. Plastic storage case is constructed of sturdy, blow-molded plastic21729 is a 40 piece tap and die set in plastic case that includes the following: tap and 1" hexagon die sizes 4-40 NC taper, 6-32 NC taper, 8-32 NC taper, 10-24 NC taper, 12-24 NC taper, 1/4"-20 NC taper, 5/16"-18 NC taper, 3/8"-16 NC plug, 7/16"-14 NC plug, 1/2"-13 NC plug, 10-32 NF taper, 1/4"-28 NF taper, 5/16"-24 NF taper, 3/8"-24 NF plug, 7/16"-20 NF plug, 1/2"-20 NF plug and 1/8"-27 NPT pipe, one die stock for 1" round or hexagon dies, one tap wrench for tap sizes No. 4 through 1/2", one T-handle tap wrench for tap sizes No. 0 through 1/4", one T-handle tap wrench for tap sizes 1/4" through 1/2", one thread gauge for 10 to 40 US threads, and one No. 5 screwdriver.