T1 Tool Steel - Tungsten High Speed Steel

Topics Covered

Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations


Tungsten is a good carbide former used in high speed steels and hot forming tool steels. It is a steel gray metal that increases temperature and red hardness, prevents gain growth and improves toughness of steels.

Tungsten high speed tool steels or group T steels range from T1 to T15 series. This article on tool steel type T1 will focus on the chemical composition, physical, mechanical and thermal properties and other designations of T1 tool steels.

Chemical Composition

The chemical composition of T1 tool steels is outlined in the following table.

Element Content (%)
C 0.65-0.80
Mn 0.10-0.40
Si 0.20-0.40
Cr 3.75-4.00
Ni 0.3
W 17.25-18.75
V 0.90-1.30
Cu 0.25
P 0.03
S 0.03

Physical Properties

The following table shows the physical properties of T1 tool steels.

Properties Metric Imperial
Density 8.67 g/cm3 0.313 lb/in3

Mechanical Properties

The mechanical properties of T1 tool steels are displayed in the following table.

Properties Metric Imperial
Hardness, Rockwell C 63.0 - 65.0 63.0 - 65.0
Poisson's ratio 0.27-0.30 0.27-0.30
Elastic modulus 190-210 GPa 27557-30457 ksi

Thermal Properties

The thermal properties of T1 tool steels are given in the following table.

Properties Conditions
T (°C) Treatment
Thermal expansion 9.7 x 10-6/ºC 20-200 more -
Thermal conductivity 19.9 x W/m-K 100 more -

Other Designations

Equivalent materials to T1 tool steels are:

  • AFNOR 18-04-01
  • DIN 1.3355
  • UNI X 75 W 18 KU
  • JIS SKH2
  • B.S. BT 1
  • AMS 5626
  • ASTM A600
  • FED QQ-T-590
  • SAE J437
  • SAE J438

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