High-Grade Ageing Plastic Die Steel

Chemical Composition C Si Mn P S Mo Ni Cu Al
(Typical analysis %) 0.15 0.22 1.80 0.011 0.004 0.30 2.95 1.00 0.90


  • YTJ80 is a precipitation or age-hardened mold steel with a uniform through hardness of approximately 40 HRC.
  • Good uniformity of hardness, HRC (+/-) 1-1.5
  • Ageing state can be machine worked, and the layer of electro erosion machining can be removed easily.
  • Stress relieving not required after machining.
  • Good polish. Through Electro Slag Remelting (ESR), molten steel of YTJ80 is pure, and the composition of
    YTR80 is well-distributed which gives YTJ80 better minute surface.
  • Good weldability.


  • Delicate and complicated plastic moulds.
  • Specular (transparent) lens molds.
  • Plastic mould to manufacture delicate ablation cross-hatching (dermatoglyph) car garnish, office supplies, etc.

Steel density 7.98g/cm3

General method of heat treatment

General Method of heat treatment