Sturdy shape especially for use with electric or compressed air impact wrenches. With cross hole and snap ring groove for securing sockets. Internal square to DIN 3121. With nut and bolt protection profile similar to AS-Drive profile.
External square to DIN 3121 − Form E 6.3 with spring pin. Internal square to DIN 3121 - Form G 6.3.
Chrome molybdenum steel, surface burnished.