Types of Plastics and Guidelines for Selecting Steel for the Cavity

　When the steel material for the cavity is selected depending on the type of plastic resin and the functions expected of the molded product.
　If the selection of the steel is not appropriate, it may not be possible to polish the fined surface into a fine surface, or corrosion may progress during the molding, or the wearing out may occur at a fast rate.
　The table below shows the major types of plastic resins or the guidelines for selecting the recommendation of steel.

Plastic resin Example of molded product Characte- ristics expected of the plastic resin Characte-ristics expected of the steel Recommend- ed type of steel Thermo- Plastic Resin PP ABS Bumpers OA chassis Shock resistance Surface gloss S50C SCM440 PS PMMA ABS Lighting fixtures General goods Containers for cosmetics Design flexibility Surface gloss Mirror finishing SKD61 Pre- hardened steel POM PA Gear wheels Bearings Abrasion resistance Abrasion resistance SKD61 Pre- hardened steel PC PMMA Lenses Light guides Transparency Optical transmittivity Mirror finishing SUS420J2 Precipitation hardened steel PC PMMA CDs DVDs Optical transmittivity Optical birefringence characteristics Mirror finishing Corrosion resistance SUS420J2 PVC Rainwater pipes Flaming resistance Corrosion resistance SUS Fire resistant ABS TV cabinets Consumer electronics components Flaming resistance Corrosion resistance SUS420J2 Pre- hardened steel PBT-GF PA-GF Camera chassis Electrical components Durability Abrasion resistance Pre- hardened steel SKD11 PA with magnetic powder added Printer rollers Sensor components Formability Electrical characteristics Non- magnetic characte-ristics Abrasion resistance Non- magnetic steel Mg Forming PC chassis Mobile phone chassis Durability Light weight Heat resistance Abrasion resistance Non- magnetic steel Thermo- Set Resin Phenol resin Melamine resin Kitchen utensils Ash trays Heat resistance Abrasion resistance Pre- hardened steel SKD11 Phenol resin Un-saturated polyester Switches Connectors Heat resistance Flaming resistance Abrasion resistance Corrosion resistance SUS420J2 SKD11 Epoxy resin IC sealing Transistors Electrical insulation Abrasion resistance Corrosion resistance SUS420J2 SKD11