Each drill bit is clearly labeled with its size. (T5 solid head). It features a quenched core and a manganese phosphate surface. 1/4" Hex-Shank quick release with a bit holder. [Upgraded Industrial Strength Material] Torx security bit Set are made of solid S2 alloy steel with a hardness reaching 60 HRC, torsion zone to absorb torque peaks to avoid breakage.
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