Intermediate-hardening heat treatment. Urrea offers hand operated bits (for screwdrivers and ratchets) and power operated bits for use on air tools. They feature an optimal quality-to-price ratio thanks to our tempering system and controlled manufacturing processes. Urrea guarantees uniform quality by selecting adequate materials for each one of the following applications. Key sizes for every day use. Bits made of S2 alloy Steel for exceptional strength and durability. The sets includes: Hexagonal: 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 10 mm. Torx Tamper-proof: T6, T7, T8, T9, T10, T15, T20, T25, T27, T30, T40. Slotted: 3×0.5 mm, 3.5×0.6 mm, 4×0.5 mm, 4.5×0.6 mm, 5×0.8 mm, 5.5×0.8 mm, 6×1.0 mm, 6.5×1.2 mm, 7×1.2 mm, 8×1.2 mm. Phillips: PH0, PH1, PH2, PH3. Pozidrive: PZ1, PZ2, PZ3. Square Robertson: RB0, RB1, RB2, RB3.