Description GM Chevy Torsion Bar. Heavy Duty, Forged Steel. Larger 7/8″ diameter threads. Premium heavy duty tool is designed to hold the torsion bar while you make adjustments. Please check vehicle applications below. **** This tool can only used with hand wrench.. THIS CANNOT USED WITH AIR IMPACT DRILL …. Features Material: heavy duty, forged steel Thread diameter: larger 7/8″ diameter threads (compare to competitors with only 3/4″ threads) .