Force = mass x acceleration this has been a simple yet very powerful concept since isaac newton’s time. At Spring Tools, we create tools based on this principal. Our tools are about the size of a ball point pen yet have over 3500 lbs of striking impact and use No other outside force such as a hammer. Simple is good the spring tool concept is designed to re-direct energy in a very concentrated area between (2) very strong carbon steel pieces that are permanently connected by a spring made out of high tensile strength music wire. So good that we guarantee our nail sets & center punches to be the best in the world. Easy to use energy can be released in very small finessed tapping motions on precision work surfaces such as fine wood. Longer pulls can deliver a whopping impact that can drive a large box nail through a piece of lumber or center punch through cold rolled steel. The old way all spring tool products are made with industrial grade materials and have been designed for the professional tool user. Our tools are designed and made in the U.S.A.