These super sharp cutters have a flat back for a perfect flush cut and have been hardened to the limits to stay sharp. They should be used with one jaw on the bottom of the rail so they cut vertically – doing this gives the cleanest and most stable cut and lessens stress on the tool, lengthening life. Use ONLY for nickel silver, brass or mild steel rail (Do not cut turnout actuators or track pins which will damage the super fine sharp jaws).