Hi and welcome to Metal Supermarkets the convenience stores for metal. I’m Jason Jackson, Operations and Development Manager. In our past four video blogs we’ve been looking at the main types of Steel using our acronym C.A.S.T. which stands for carbon steel, alloy steel, stainless steel and tool steel. In the final part of this series we will look at the “T” Tool Steel Tool steel can be divided into six groups water hardening, cold working, shock resisting, high speed, hot working, and special purpose. Under the AISI and SAE systems Tool steel grades are classified by the following letter codes: W is for water hardened steels This grade is essentially plain high carbon steel that has been water quenched. Added vanadium helps to increase the toughness. O is for cold worked steels that have been oil hardened. A is for cold work steels that have been air hardened. And D is for cold worked steels that have high carbon and high chromium. These cold work grades typically have high hardenability and wear resistance with average toughness. Both the oil and air hardened grades reduce the distortion caused by quick water quenching and are less likely to crack. The D grade class contains approximately 10% – 13% chromium and typically retains its hardness at increased temperatures. S is for shock resisting steels which are designed to resist shocked at both low and high temperatures. They also have high impact toughness and relatively low abrasion resistance. H is for hot working steels and depending on the grade number are either chromium based, tungsten based, or molybdenum based. These steels are developed to maintain strength and hardness while exposed to prolonged elevated temperatures. M is for high-speed molybdenum based steels. T is for for high-speed tungsten based steels. These high-speed grades are used for cutting tools where strength and hardness must be retained at high temperatures. P is for plastic mold steel which are designed to meet the needs of zinc die casting and the special requirements of plastic injection molding dies. L is for low alloy, special purpose steels. and F is for carbon tungsten based special purpose steels which are water hardenable and more wear resistance than W type tool steel. Hopefully this video has given you a better idea of common classifications of tool steel. Don’t forget to check out the other videos from this series for more details on the four main types of steel. If you need tool steel for your next project Metal Supermarkets is the world’s largest supplier of small-quantity metals carrying over 8,000 types, shapes and grades of metal including various tool steel grades cut the size and ready fast!