Striking face wrenches are designed to be struck by a hammer on the anvil area in order to loosen frozen fasteners or to set and tighten fasteners. Anvils are proportional to opening sizes. Special heat treating provides maximum durability for long life. Offset handle is close to head to provide clearance in confined areas. Williams' expanded line of offset striking face wrenches, up to 4-1/4", provides the most extensive line on the market. Specifically engineered to hold up under the most rigorous industrial use.