The carbon content of high speed tool steel is on the range for 0.70% – 1.65%. The alloy content is on the range of 10% – 20%. That improves the hardness, hardenability, wear resistance and hot hardness dramatically. There are all kinds of alloy carbide inside, it still has a high hardness at the 600℃ high temperature. They are suitable for making cutting tools with high cutting speed requirement. And also good for the big size or small size cutting tools that have high requirement for high wear resistance. And it is used to make the molds, roll and machine fittings with high wear resistance requirement.
According to the different alloy elements, high speed tool steel can be divided into tungsten high speed steel, molybdenum high speed steel, cobalt high speed steel, high-vanadium high speed steel and etc. So different grade tool steel of it has different applications. As below, I will show the details for you.
Applications and Grades of HSS Steel
- GB W18Cr4V / ASTM T1 / JIS SKH2
GB W18Cr4V is equivalent to ISO HS18-0-1, ASTM T1, UNS T12001, JIS SKH2, DIN S18-0-1-B18. This steel belongs to the tungsten high speed steel, it has higher toughness, hot hardness and high-temperature hardness. It’s not easy to get overheated during the quenching, but the machinability is good. The disadvantages for it are bad thermoplasticity and toughness.
It is suitable for the cutting tools with high speed cutting, including lathe tool, drill bit, milling cutter and etc. And also can be used to make screw tap, wire-drawing die, saw web and etc.
- GB W18Cr4V2Co8 / ASTM T5 / JIS SKH40
GB W18Cr4V2Co8 steel is equivalent to ISO HS18-0-1-10, ASTM T5, UNS T12005, JIS SKH40, DIN S18-1-2-10 steel. It also is the tungsten high speed steel, but it has the cobalt element. Its hot hardness, high-temperature hardness and wear resistance are better than GB W18Cr4V. But the toughness gets down.
It is a good choice for making the tools with the complex conditions for the working, such as lathe tool, willing cutter, hob and more.
- GB W12Cr4V5Co5 / ASTM T15 / JIS SKH10
The equivalent steel grades for GB W12Cr4V5Co5 are ISO HS12-1-5-5, ASTM T15, UNS T12015, JIS SKH10, DIN S12-1-4-5. It is the tungsten high speed steel with cobalt and high vanadium. It has great hardness and wear resistance. But the machinability, strength and toughness are bad. It is not a good choice to make complex cutting tools with high speed cutting.
It is suitable for making cutting tools with special wear resistance requirements. Such as the thread chasers, drawknife and etc. And it also can be used to make the cold-work dies.
- GB W6Mo5Cr4V2 / ASTM M2(Regular C) / JIS SKH51 SKH59
GB W6Mo5Cr4V2 steel is equivalent to ISO HS6-5-2, ASTM M2(Regular C), JIS SKH51 SKH59, DIN S6-5-2. This steel has good hot hardness and toughness. After quenching, the surface hardness can be 64HRC – 66HRC. It is one of the most popular high speed tool steel.
It is a good material for the drill bit, screw tap, milling cutter, cold work mold and etc.
- GB CW6Mo5Cr4V2 / ASTM M2(High C) / DIN SC6-5-2
GB CW6Mo5Cr4V2 is equivalent to ASTM M2(High C), UNS T11302, DIN SC6-5-2. After the quenching, its wear resistance, high-temperature hardness, thermostability, surface hardness all better than W6Mo5Cr4V2. But the strength and impact toughness are got lower.
It was be used to make the cutting tools with high machinability. Such as the broach, reamer, hob and etc.
- GB W2Mo9Cr4V2 / ASTM M7 / JIS SKH58
GB W2Mo9Cr4V2 is equivalent to ISO HS2-9-2, ASTM M7, UNS T11307, JIS SKH58, DIN S2-9-2. It has good wear resistance, hot hardness and toughness. And the density is small, the machinability is good, the performance for cutting the common material is great.
And it is suitable for milling cutter, screw tap, saw blade, lathe tool, broach, cold-punching mold and etc.
- GB W6Mo5Cr4V2Co5 / ASTM M35 / JIS SKH55
GB W6Mo5Cr4V2Co5 is equivalent to HS6-5-2-5, ASTM M35, JIS SKH55, DIN S6-5-2-5. It is the cobalt high speed steel. It has good wear resistance, machinability, hot hardness and high-temperature hardness. But the strength and impact toughness is not high.
It can be used to make all kinds of cutting tools, such as the punches, milling cutter and etc.
- GB W7Mo4Cr4V2Co5 / ASTM M41
GB W7Mo4Cr4V2Co5 is equivalent to ISO HS7-4-2-5, ASTM M41, UNS T11341, DIN S7-4-2-5. At the base of the W6Mo5Cr4V2Co5 to add 5% cobalt content. And increase the carbon content and adjust the content of tungsten and molybdenum. Which help the steel to get higher red hardness and high temperature hardness. And improve the wear resistance. Its machinability is good, but the strength and impact toughness are lower.
It also be used for gear cutter, milling cutter, punches and more.
- GB W2Mo9Cr4VCo8 / ASTM M42 / JIS SKH59
GB W2Mo9Cr4VCo8 is equivalent to ISO HS2-9-1-8, ASTM M42, UNS T11342, JIS SKH59, DIN S2-10-1-8. It is high carbon high cobalt high speed steel. It has high hot hardness, high-temperature hardness and machinability.
This steel is suitable for all kinds of high precision complex cutting tools. Such as the forming milling cutter, individual drill bit, lathe tool and etc.