Acc. to DIN 838, ISO 3318, ISO 1085, ISO 10104, GEDORE vanadium steel 31CrV3, chrome-plated, * not standardised, Satin non-glare finish, Carefully forged and professionally machined: Ring: thin-walled, 5° deep offset from shaft, with UD profile for gentle transmission of force, High bending strength - does not fracture or splinter when overloaded, thus minimising the risk of injury, Overloading indicated by deformation, For extremely deep or inset bolts, Top-grade industrial quality for the hardest of continuous use