The difference between NAK80 and S136

injection mold steels NAK80 S136

NAK80 is a precipitation hardening steel for high-grade mirror plastic molds.

. After solution treatment and age hardening, the hardness is able to reach up to 37-43 HRC.

  • Able to be used in the original state without heat treatment.

. Ni-Al-Cu is an age hardening steel.

  • Great machinability.
  • Easily polished after electro discharge machining (EDM).
  • Great weldability.
  • Low deformation during use ensures high accuracy.
  • Uniform hardness of the surface and the center.

. Special smelting

  • Outstanding mirror polishing, with satisfactory glossiness.
  • Great texturing.
  • After EDM, the surface is delicate and beautiful, able to replace refined texturing.

S136 is a plastic mold steel with excellent corrosion resistance, which boasts outstanding production characteristics. Its advantages are listed below:

  • Low maintenance cost:

With S136 as the mold steel, the surface of the mold cavity still maintains the original smooth state after long-term usage. When the mold is operated or stored in a humid environment, no special protection is required.

  • Low production cost:

The mold is not corroded though affected by the coolant. Since there is a certain cooling cycle, the mold service life is therefore increased. Based on its high corrosion resistance, S136 can be used to produce molds with a low maintenance cost and a long service life to achieve the best economic benefits. At the same time, S136 is refined by electroslag remelting (ESR), so that it features a pure and fine structure, allowing the mold great comprehensive mechanical properties and a super high polishing performance.

Difference in Composition (Main Alloying Elements)

Steel Type C Si Mn Cr Mo V Ni AL Cu
NAK80 0.05-0.18 0.15-1.00 1.00-2.00 0.10-0.40 2.50-3.50 0.50-1.50 0.70-1.50
S136 0.35-0.45 0.90-1.20 0.40-0.70 13.0-14.0 0.25-0.35 0.15-0.30

Difference in Hardness
NAK80 is an age hardening steel, which has been pre-hardened to 38-42 HRC. Without having to be heat treated, it will never deform.

S136 requires heat treatment to harden.

Difference in Texture
NAK80 is able to be mirror polished, and its texture is easier to be removed (than that of S136).

It is not easy to remove the texture of S136 during polishing.

Difference in Corrosion Resistance
NAK80 is not corrosion resistant, so it is not applicable if the plastic material is corrosive.

S136 is corrosion resistant, and doesn’t rust easily.

Difference in Purpose
NAK80 is suitable for the production of shell molds of tablet screens with mirror polishing requirements; cameras; audio equipment; transparent covers and films, etc.

S136 is suitable for plastic molds that require high corrosion resistance and mirror polishing.

Polishing Process
After rough machining (turning or milling)
①. Whetstone polishing (#220 → #320 → #400)
②. Sandpaper grinding (#320 → #400 → #600 → #800 → #1000 → #1200 → #1500)
③. Diamond paste (#1200 → #1800 → #3000 → #8000)

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