Drop forged steel extension bars. Suitable for use on all types of impact tool. Chrome Vanadium steel used on 3/8ins and 1/2insSq drive size. Chrome Molybdenum steel used on 3/4ins and 1insSq drive sizes which demand higher torque rates. Phosphate finish for added corrosion resistance. Spring ball socket retainer and drilled head to accept retaining pin where applicable.