Tool steel is a carbon alloy that manufacturers use for a variety of purposes, including machining and cutting. Their unique properties, including hardness, wear resistance and deformation, make them suitable for shaping other materials through cutting and machining.
This article introduces what is tool steel? What are the properties of tool steel? How is it different from stainless steel? And several factors should be considered when selecting tool steel.
What Is Tool Steel?
The steel used to manufacture various cutting tools, cold and hot deformation molds, measuring tools and other tools is collectively referred to as tool steel. All kinds of tool steels have common requirements, such as high hardness, good wear resistance, and certain toughness and strength, as well as their own special requirements, such as red hardness, impact resistance, dimensional stability, thermal fatigue resistance, and good comprehensive mechanical properties. In order to meet these different requirements, various tool steels with different compositions are used in production, and their performance requirements are met through appropriate heat treatment processes.
What Are The Properties Of Tool Steel?
This is a tool steel grade with high dimensional stability during hardening. It also has the best hardness response at low temperature. Its maximum HRC is 65.
This water hardening tool steel, also known as commercial carbon, is very suitable for use when simple heat treatment is required. It has excellent wear resistance and good toughness. Its maximum HRC is 68.
It has higher heat resistance and wear resistance than O1. Its maximum HRC is 63 with less distortion. It has excellent wear resistance and abrasion resistance.
It has excellent toughness and wear resistance. The maximum HRC of this tool steel is 65. However, it is difficult to process.
This impact resistant tool steel has high strength and ductility, but its wear resistance and abrasion resistance are average. Its maximum HRC is 61.
This special type of tool steel has a maximum HRC of 32. It is an ideal choice for processing die castings and plastic moulds
This hot work tool steel has good wear resistance and hardenability. It also has a high resistance to thermal fatigue cracking. Its maximum HRC is 54
This high speed tool steel has a maximum HRC of 65 and excellent wear resistance and toughness.
There are different grades of tool steels available for metalworking. In addition, they differ in chemical composition, temperature range and hardening type.
However, the ideal grades of machining tool steels include cold working steels such as O1, D2 and A2, and high speed steel tools such as M2. O1 has high hardness, but good machinability. This steel is very suitable for machining cutting tools and drills.
D2 also has good processability due to its high carbon and chromium content. It has good toughness and wear resistance, making it very suitable for durable processing tools.
In addition, A2 tool steel has a good balance of toughness and wear resistance. It also has good processability. This tool steel is an ideal choice for forming punches, injection moulds and trimming moulds.
Difference Between Tool Steel And Stainless Steel
Stainless steel and tool steel have different properties. This difference is due to the change of their constituent elements. Chemically, tool steel is a carbon alloy containing other alloying elements, including tungsten, chromium, molybdenum and vanadium.
For example, because tool steel contains carbides, it is very durable, machinable and wear resistant. Generally speaking, tool steel is more tough and has higher tensile strength than stainless steel. This makes them ideal for the production of heavy cutting tools. On the negative side, the lack or reduction of chromium content makes this steel easy to corrode.
In addition, stainless steel is a chromium nickel alloy with nickel, nitrogen, titanium, sulfur, molybdenum, silicon and other alloy elements. Due to the existence of chromium, it has high rust resistance and corrosion resistance. More importantly, it usually has a smooth, bright, shiny surface.
If you are choosing the right tool steel grade for your particular application, here are some important things you must thoroughly consider.
Shock And Impact
Some types of tool steels are often hard and brittle, which makes them easy to fracture once encountering large impact. Fortunately, impact resistant tool steels have commendable toughness and can withstand impact and shock. However, one disadvantage of this kind of tool steels is that their overall hardness and wear resistance decrease slightly. Therefore, anti-seismic tool steel can only be used for tools that are expected to face huge and sudden impact in daily applications. Chisels, shears and hammers can be made of anti-seismic tool steel.
Another thing to consider when selecting the appropriate tool steel grade is the exposure of the tool to high temperatures. You see, most tool steels are heat treated. If the tool steels are reheated again, their hardness and wear resistance may be reduced because it is contrary to the previous heat treatment process. For high temperature applications, you must choose hot tool steels because they do not lose their core valuable properties even when exposed to high temperatures. Hot work tool steel is suitable for making moulds and hot scissors.
Low temperature application will also affect the overall performance of the tool. Therefore, your tools must be made of cold work tool steel so that they can effectively withstand the destructive effects of low temperatures. The chromium, manganese and molybdenum content of this tool steel grade is increased, which prevents it from going through the rapid quenching process. Although the existence of these alloy elements makes cold work tool steels more expensive than other tool steels, they still help these tool steels to obtain good mechanical properties. Cold worked steel is very suitable for punches, dies and gauges.
High Speed Level
There are several tools that will be used for rapid movement and operation. Using the wrong grade of tool steel may reduce the hardness and wear resistance of your tool. In addition, your tools will wear out quickly once used in high-speed applications. In order to prevent these conditions from occurring on your tools, you must use high-speed tool steels to manufacture them, because they have high wear resistance and high temperature resistance. High speed tool steel can be used to make drill bits, pump parts and cutting blades.