Plastic Injection

– Pre Hardened –


Pre hardened (40 HRC) modified tool steel for plastic applications with ESR properties. Better cleanliness, homogeneity and polishability than 2738 HH.

Chemical Composition

Special chemical composition.

Material Properties

  • High hardness (Prehardened).
  • Uniform hardness across the cross-section area.
  • Very good homogeneity and cleanliness
  • Very good Polishability.
  • Very suitable for texturing.
  • Good weldability.
  • Good machinability even if it is prehardened up to 40 HRc.
  • The recommended working hardness is the delivery hardness.
  • Very good nitriding and coating ability.
  • Very good dimensional stability while nitriding.


  • Cavities and cores in the plastic Injection molds with surface quality up to A1 and A1+:
    • Automotive interior trimming dies.
    • White goods’ panels.
    • Packaging molds.
  • Injection molds of transparent parts.
  • In extrusion dies of non-corrosive plastics.
  • Machinery equipment, wearing plates.
  • Plastic pressing, compression dies.
  • Use nitriding if the reinforcement more than 20%

Heat Treatment

Soft Annealing 710-740°C
Stress Relieving 550-600°C
Hardening 870-900°C
Tempering 560-650°C

Physical Properties

20°C 200°C 300°C
Elastic Modulus [kN/mm²] 212 207 194
Thermal Expansion Coefficient [10ˉ6/K] 11 12,5 12,8
Thermal Conductivity [W/mK] 41

Delivery Condition and Comparison

Hardness HB Hardness HRc Tensile Strength N/mm2
Vega 40 350-390 38-42 1150-1290
1.2738 HH 320-350 34-38 1085-1200
1.2738 280-320 30-34 965-1085

Microstructural Cleanness

ASTHM E45/97  Method: A. Plate: I-R

A (Sulphide Type) B (Alumina Type) C (Silica Type) D (Globular Oxide Type)
T (Thin) H (Heavy) T H T H T H
0,5 0,5 0,5 0,5 0 0 1,0 0,5

Tempering Graph