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.