The average lay person thinks of steel as just being steel. However, your local shop that conducts heat treating in Gastonia, NC knows that steel types have subtle differences that affect its final application. That is why clients order heat treating in the first place: to get steel and other materials ready for manufacturing into products. To make this transition more successful, steel undergoes stringent classification so its properties are better understood for heat treating and manufacturing. Here are these categories.
Material steel
Steel that is used for manufacturing applications is referred to as material. It is the most common metal that undergoes heat treating, although alloys with copper and titanium frequently undergo heat treatment, as well.
The Society of Automotive Engineers and the American Iron and Steel Institute use a shared numerical system to describe the properties of different steel types. The numbers indicate the amount of carbon and other alloys mixed in during processing. A general category of “plain steels” describes those made from iron and carbon, while alloys include carbon, iron and one other metal.
Carbon is described using a “points” system that indicates the metal’s strength. Using four numbers, the categorization system indicates steel type by the first two numbers, and the amount of carbon with the last two. The common types (and their numbers) include plain carbon (10), nickel-moly (46), free cutting (11), chromium (52), nickel-chromium (31), chrome-vanadium, chromium-moly and nickel-chromium-moly (86). The higher the amount of carbon, the better it will endure hardening.
ASE 1040 steel indicates plain steel with 40 carbon points, and it is a typical material for machine parts. Cutlery and knives will rate high—high-quality kitchen utensils are normally made from ASE 1095. The same system applies to the other types of steel, as well. A mid-range nickel-chromium, for example, would be indicated by ASE 3140.
Tool steel
Tool steels are special purpose alloys. They have their own classification system that designates how they were heat treated. For steels that were water hardened, they will be designated “W.” Other classifications indicate a range. Chromium hot work is designated H11 to H16, depending on its tolerance and composition. Other categories also included in this system include moly hot work, shock resisting, tungsten high speed, moly high speed, oil hardening, air hardening, low alloy special and many other specialized descriptions.
Industries that make tools will require more specific classifications for their material. To make good products, there has to be more information beyond the type of steel and carbon points. This system gives a more exact description to determine possible applications and if any further heat treatment is required.
Unless you pursue the lower quality steels, almost any material or tool steel can be improved or changed through heat treatment. With material steel, anything with 20 carbon points or lower will not benefit from heat treatment. As these grades are normally reserved for nails, wire and general use, it is unlikely you will come across this type of steel for industrial applications.
If any of your tools, machine parts or other steel material requires heat treating in Gastonia, NC, contact J.F. Heat Treating Inc. Our professional metallurgical lab offers a full range of heat treating services.