This is our brand new 20 pcs Tin Coated End Mill Set which is made of M2 hardened high speed steel that will stand years of use. It Includes 20 pieces of the most popular sizes fitted in a sturdy wooden case. Don't hesitate to buy one now! Brand new and high quality Heavy duty and solid construction Center Cutting Design Allows Mills To Be Used As Drills Each size Comes in 2 Flutes and 4 Flutes Material: M2 hardened high speed steel Package includes 2 of each size: one 4 flute and one 2 flute 3/8" Shank : 3/16", 1/4", 5/16", 3/8", 7/16" 1/2" Shank : 1/2", 9/16" 5/8" Shank : 5/8", 11/16" 3/4" Shank : 3/4"