High Speed Steel, Titanium Nitride Coated ;Tri-flat shank for sure grip ;Storage in Aluminum Carry Cases(2) ;Include Sizes of SAE Case: 1 PC--1/4" Shank--6 Steps: 3/16, 1/4, 5/16, 3/8, 7/16, 1/2" ; 1 PC--1/4" Shank--13 Steps: 1/8, 5/32, 3/16, 7/32, 1/4, 9/32, 5/16, 11/32, 3/8, 13/32, 7/16, 15/32, 1/2" ;1 PC--3/8" Shank--9 Steps:1/4, 5/16, 3/8, 7/16, 1/2", 9/16, 5/8, 11/16, 3/4" ;1 PC--3/8" Shank--12 Steps:3/16, 1/4, 5/16, 3/8, 7/16, 1/2, 9/16, 5/8, 11/16, 3/4, 13/16, 7/8" ; 1 PC-1/2" Shank--10 Steps:1/4, 3/8, 1/2, 5/8, 3/4, 7/8, 1, 1-1/8, 1-1/4, 1-3/8" ;Include Sizes of Metric Case: 1 PC--1/4" Shank--5 Steps: 4mm, 6mm, 8mm, 10mm, 12mm ;1 PC--1/4" Shank--9 Steps: 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm ;1 PC--3/8" Shank--7 Steps: 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm ; 1 PC-5/16" Shank--10 Steps: 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm ; 1 PC--3/8" Shank--15 Steps: 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, 32mm.