Die materials

We supply die materials designed to meet our customers' needs.


SD steel as plastic forming die material

  • Pure steel made with a special refining method is used.
  • Optimal heat treatment is used to produce steel material with little treatment distortion.
  • Using fixed forging greater uniformity of the inside and outside structures is achieved.
Fixed forging reduces directionality.

Without fixed forging

With fixed forging

  • Carrying out special treatment, surface texturing is improved.
  • Using shape forging, we can make materials that are close to the shape of the product.
Examples of shaped products

Automobile bumpers

Bath tub core

Bath tub cavity

Die materials for hot forging SDH steel / DK steel

  • We have the largest crankshaft forging line in Japan. We supply die materials based on the experience we have gained in its operation.
  • We select die materials and surface treatments based on the knowledge we have acquired from the results obtained in the operation of our own line.


Types and applications of SD steel
Steel types Standard Hardness Hs (HRC) Applications
SD18T JIS S55C improved 30±2 (13) S55C free-cutting steel with high thermal conductivity
SD77 AISI P20 equivalent 41 - 46(31) P20 equivalent material with good weldavility, machinability and wear-resistance
SD100 47±2 (34) wear-resistance
Mechanical properties of SD steel
Steel types Yield point
Tensile strength
Reduction of area
Impact value
SD18T 430 720 25 47 38 - 44 30
SD61 666 872 22 63 88 - 196 38
SD77 859 969 19 49 41 - 46 42
SD100 911 1078 18 55 49 - 69 47
Die materials for hot forging SDH steel / DK steel
Standard Steel types Properties Applications
Wear-resistance Heat-cracking resistance Fracture-resistance Machinability
SKT4 improved SDH21 B B B A For hammer forging
SKD61 improved SDH3 B A A+ B For hot forging
DK65 A A B B

Super [A+・A・B・C] Inferior

Contact Information

For further product information

Product Quotes, and inquiries without complete information required in inquiry form may not be responded to. Selection of inquiries for reply online is at the sole discretion of Nippon Steel. We appreciate your understanding.