1. Material for injection mold.

Normally, steel is the material that guaratees reliably functioning molds with service lives provided a suitable steel grade has been selected from the assortment offered by steel manufacturers and this grade has been treated so as to develop a structure that provides the properties required in use. This calls first for a suitable chemical composition. The individual alloying elements have positive as well as negative effects on the desired characteristics. Generally several alloying elements will be present, wich can also mutually affect one an other. The requirements result from the wishes of the molder and the mold maker. The folowing properties are expected from steels :

• Caracteristics permitting economical machining.

• Capacity for heat treatment without problems.
• sufficient toughness and strenght.
• Case of polishing.
• Resistance to heat and wear.
• High thermal conductivity.
• Low cost notch sensitivity.
• Corrosion resistance.

Effect of alloying element on the characteristics of steel.

Steel is basically iron alloyed to carbon with certain additional elements to give the required properties to the finish melt. Listed below is a summary of the effects various alloying in steel.

Many various steel distribute in the market, like Assab steel, Daido steel, Hitachi etc.

Assab Plastics mold steel

Assab hot working steel

Assab cold working steel

Daido plastics mold steel

Daido hot working steel

Daido cold work steel

Daido HSS

Application steel for part mold as experience.

If you need steel with hard enough (more than 30 Hrc), good corrosion resistance, good polishability  and directly using without heat treatment like for fix cavity, moving cavity, core, moldbase etc :

• s-star (Daido)
• 2316 (Thissenkrupp)
• PK335(Metalravne)
• Corax, Ramax (Uddeholm)
• Royalloy (assab)

If you need steel hard enough (less than 25Hrc), with good corrosiont resistance, good polishability and direcly using without heat treatment like for fix cavity, moving cavity, core, moldbase etc :

• M300 (Bohler)
• Tyroplast2316 (Edelstahl)
• Elmax (Uddelholm)

If you need steel with good resistance, good polishability, able to heat treatment more than 50 Hrc for long run of production like for fix cavity, moving cavity core etc :

• S-star (Daido)
• Stavax esr, Polmax, Mirrax esr (Uddelholm)
• HPM38 (Hitachi)
• Thyroplast2083 (Edelstahl)
• PK4EX (Metalravne)

If you need steel with hard enough stenght (more than 30 Hrc)without corrosian demand like for fix cavity, moving cavity, core , moldbase etc :

• 718 supreme (Uddelholm)
• M200 (Bohler)
• PX4 (Daido)
• Nak80 (40 Hrc) (Daido)
• HPM7 (Hitachi)

If you need steel with superior hardness (more than 60 Hrc) and good dimensional stability after heat treatment, superior wear resistance for long run production like for sleeve, core sleeve etc., usualy this steel useful for hollow part especialy thin wall part :

• Asp30 (Uddelholm)
• S705 (Bohler)
• MH55 (Daido)

If you consider with thermal conductivity , so you can chose non metal like copper alloy  for your fix cavity, moving cavity, core or only insert.
Berrylium-copper :

• Moldmax HH (Uddelholm)
• BrocadurB20 (Brower metal)

Copper alloy non berrylium :

• Moldmax XL (Udelholm)
• Brocadur CNCS (Brower metal)
  

If you need steel for gear, shaft or machinery part, you can use :

• 705M (uddelholm)
• VCN150 (Bohler)
• DAC439 (Daido)
• NS4340 (Hitachi)
• VCNMo150 (Metalravne)

 For standard moldbase you can use :

• 760 (Assab)
• .
• etc.

Of  course the steel have difference one with other, so you can chose depend on :

• Characteristics permitting economical machining.
• Chapacity for heat treatment without problems.
• Sufficient toughness and strenght.
• Case of polishing.
• Resistance to heat and wear.
• High thermal conductivity.
• Low notch sensitivity.
• Corrosion resistance.

Sources :
How to make injection mold ?
Assabindonesia.com
Daido.co.jp
hitachi-metal.co.jp

<<BACK HOME>>