What is tool steel?



Tool steel is the steel be used to manufacture cutting tools, measuring tools, moulds and antifriction Tool.


Tool steel with high hardness and under high temperature to keep high hardness and red hardness, and high wear resistance and appropriate toughness.


Tool steel is generally divided into carbon tool steel, alloy tool steel and high-speed tool steel.

Carbon tool steel

Steel of Carbon content between 0.65% to 1.35%,?Non alloy steel.

According to?Microstructure?distinguish, the carbon tool is belong to high carbon eutectoid,?hypoeutectoid, ?second? eutectoid steel.

After heat treatment, the surface of carbon tool steel can get higher hardness and wear resistance, and the core of the tool has good toughness, and the annealing hardness is lower (less than HB207), and the processing performance is good. But its red hardness difference, when the working temperature of 250 degrees, the hardness and wear resistance of the steel decreased sharply, the hardness decreased to HRC60, this kind of steel is low. The larger tool can not be quenched (the diameter of the water is 15mm), the surface hardened layer and the central part of the hardness vary widely. Make the tool easy to produce deformation during quenching. In addition, the quenching temperature range is narrow and the temperature should be strictly controlled during quenching. To prevent overheating, decarburization and deformation.

Carbon tool steel?typical steel grade?as below:

W1-A SK1 T7 1.1620 C70E2U
W1-C SK2 T8 1.1625 C80E2U
W2-A SK3 T9 1.1830 C90E2U
W2-C SK4 T10 1.1546 C105E2U
W5 SK5 T11 1.1645 C120E3U
SK6 T12 1.1663 C140E3U
SK7 T13 1.1520 C105E2U


Alloy tool steel

Alloy tool steel is a special quality Medium carbon or High carbon alloy steel(?Carbon content >0.25%). ?Alloy tool steel’s?Quenching, quenching, wear resistance and toughness all higher than carbon tool steel.

According to the purpose can be roughly divided into cutting steel, mould?steel and measuring tool steel 3 classes.

High carbon content of steel (carbon mass fraction is more than 0.80%) used in the manufacture of cutting tool and measuring tool and cold work mould, this kind of steel after quenching hardness above HRC60, and have enough resistance to wear; Medium carbon content of steel (carbon mass fraction 0.35% ~ 0.70%) used in the manufacture of hot-work die more, this kind of steel after quenching hardness is a bit low, to HRC50 ~ 55, but toughness is good.

milled cutting knife hss-244high speed steel HSS drillcold work tool steelS2 tool steelS2 tool seel

Alloy?tool steel?typical steel grade?as below:

L3 SKS2 Cr2 90CrSi5 130Cr3
L6 SKS4 Cr8 1.175 Y100Cr6
F1 SKS5 Cr12 100Cr6 X200Cr12
S1 SKD1 Cr12Mov 90Cr3 X160CrMoV12
S7 SKD4 Cr12Mo1V1 1.2414 X100CrMoV5
H11 SKD6 CrWMn 1.208 105WCr5
H13 SKD8 9CrWMn 1.2083 90MnWCrV5
H21 SKD10 5CrNiMo 1.2311 55NiCrMoV7
A2 SKD11 3Cr2Mo8V 1.2312 X30WCrV9
A3 SKD12 4Cr5MoSiV1 1.2343 X38CrMoV5
A7 SKD61 4Cr5MoSiV 1.2344 X40CrMoV5
A8 SKT4 3Cr2Mo 1.2713
D2 1.2714
D3 1.2581
D5 1.2379
D6 1.2542
O1 1.2365

③High speed steel

High-speed steel (HSS or HS) is a high carbon and high alloy tool steels, commonly used in tool bits and cutting tools.

It is often used in power-saw blades and drill bits.

It is superior to the older high-carbon steel tools used extensively through the 1940s in that it can withstand higher temperatures without losing its temper (hardness). This property allows HSS to cut faster than high carbon steel, hence the name high-speed steel. At room temperature, in their generally recommended heat treatment, HSS grades generally display high hardness (above HRC60) and abrasion resistance (generally linked to tungsten andvanadium content often used in HSS) compared with common carbon and tool steels.

High Speed?steel?typical steel grade?as below:

T1 SKH2 W18Cr4V 1.3355 HS18-0-1
T4 SKH3 W18Cr4VCo5 1.3255 HS18-1-1-5
T5 SKH4 W18Cr4V2Co8 1.3202 HS18-02-9
T15 SKH10 W12Cr4V5Co5 1.3343 HS112-1-5-5
M2 SKH9 W6Mo5Cr4V2 1.3342 HS6-5-5HC
M3 SKH52 W6Mo5Cr4V3 1.3344 HS6-5-3
M7 SKH51 W2Mo9Cr4V2 1.3348 HS2-9-3
M35 SKH53 CW6Mo5Cr4V2 1.3246 HS2-9-1-8
M42 SKH59 W2Mo9Cr4VCo8 1.3207 HS10-4-3-10
1.3249 HS7-4-2-5


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