Prime Straight Ring Type Striking Wrenches are designed to be struck by a hammer on the anvil area, specially designed for most rugged industrial application in order to loosed frozen nuts or to tighten fastener. Anvil are proportional to wrench opening size. Specially selected alloy steel & best suited heat treatment process follows for maximum durability for longer life and to withstand the severe working conditions. Industrial rust resistance black finish provides super finish and resistance to corrosion in industrial use.