The tool projects in this book make use of tool steel readily available at a reasonable price in dimensions and composition suitable for blade making. It is one way among many to make blades. The ancient art of blacksmithing is a fascinating craft in itself. Anyone wishing an introduction to it would do no better than to pick up any of Alexander Weyger’s books, The Making of Tools, The Modern Blacksmith, and The Recycling, Use and Repair of Tools (Van Nostrand Reinhold Co., New York).
What is presented here is more modest. The O1 tool steel in prepared dimension is ready for a specific blade project. It is rather like buying a milled 1 × 12 board that can enable you to begin a woodworking project. Logging, sawing green lumber, the art of drying boards, and milling smooth dimensioned stock have all gone before. It helps to know a little of that world to appreciate the finished board. Likewise, tool steel characteristics give understanding to blade making.
Three Stages of Tool Steel
Steel that has carbon in it can be shaped and hardened. The carbon is only around one percent, but its effects are many. Steel without carbon is soft and is called mild steel, and can not be hardened and tempered for blades. High carbon steel goes through three stages in blade making. Initially, it needs to be soft enough that hacksaws, drills and files can shape it. This is called annealed steel. It is still hard compared to mild steel, and a new hacksaw blade will help avoid a prolonged job of cutting the blank. To be annealed, the steel is heated 50° F to 75° F above its transformational point of 1,350° F to 1,400° F and cooled slowly. The blacksmith at his forge heats the steel and buries it in hot ash to cool. The O1 steel as it comes to you is in this annealed state.