Thunder Zone Impact driver bits, with an engineered spiral torsion zone, distributes the applied impact evenly throughout the torsion zone, allowing higher impact loads and greatly extended bit life. The ultimate torsion bit for impact drivers Patented spiral impact zone distributes torque evenly Premium Quality S2 raw material Full body hardness - for a longer service life Compression forged tip - for an ideal fit & to reduce breakage Magnetised bits HEX6 x 60mm