Titanium Twist Drill Bit Set, 135 Tip High Speed Steel, Sizes From, 230 Pcs.. Premium Material: Manufactured from high speed steel for strength and durability Storage: Supplied in a plastic storage box for easy storage and transportation Widely Used: The 135 fast cutting point is automatically centered and penetrates quickly with less pressure,The drill kit meets all your requirements, including all common size specifications for Wood/Cast Iron/Aluminum Alloy/Plastic/Fiberglass Process Treatment: Titanium coated surface prevent rusting,which increase the hardness of the drill bit and reduces heat buildup, make the twist drill bit more wear-resisting for longer life Size Includes: 32 Piece 3/64", 30 Piece 1/16", 30 Piece 5/64", 30 Piece 3/32", 20 Piece 1/8", 20 Piece 9/64", 12 Piece 5/32", 12 Piece 11/64", 12 Piece 3/16", 8 Piece 7/32", 4 Piece 15/64", 6 Piece 1/4", 4 Piece 9/32", 2 Piece 19/64", 3 Piece 5/16", 2 Piece 21/64", 1 Piece 23/64", 1 Piece 3/8", 1 Piece 1/2"