Steel type Equivalent JIS steel Hardening and annealing hardness Features Application example K3M SKS93 58 to 63HRC Carbon-tool steel Press dies, blades, gauges KS3 SKS3 58 to 63HRC General-purpose cold- tool steel Press dies, blades, gauges FH5 　 55 to 61HRC Flame-hardened steel Press dies KRCX 　 50 to 60HRC Highly machinable general-purpose cold- tool steel Flame-hardened steel Metallic molds, mold parts, jigs, press-dies RC55 　 54 to 56HRC Highly machinable pre-hardened steel Press-dies KD11 SKD11 58 to 61HRC General-purpose cold- tool steel Press-dies, rolls, gauges KD11S 58 to 61HRC Highly machinable general-purpose cold- tool steel Flame-hardened steel Press-dies, rolls, gauges KD12 SKD12 58 to 61HRC High-tenacity cold-tool steel Molds for plastic, blades KD31 　 56 to 61HRC Impact-resistant high-grade cold-tool steel Blades KPS6 58 to 60HRC Corrosion-proof, wear-proof cold-tool steel Resin forming machine parts

●Recommended! The KD11S with remarkably improved machinability by proper carbide form control without deteriorating the basic performances of the SKD11 will comply with usersﾕ expectations. "If we can only engrave molds as hard as HRC55 directly!" Koshuha complies with such a customerﾕs dream. The RC55 is new pre-hardened steel that enables steel as hard as HRC55 to be machined efficiently at low cost without the need of special cutting tools. It requires no thermal processing and offers improved mold precision and reduces the manufacturing time. The KRCX is multi-purpose cold-tool steel that remarkably improves the machinability, tenacity, and hardening performance and may be hardened in the same conditions as the SKD11 and SKS3. It also demonstrates superior performance as flame-hardened steel with high tenacity and high machinability. The KPS6 is high-tenacity tool-steel with improved corrosion resistance and wear-resistance suitable to the screws for plastic-forming machines.

●Positions of cold-tool steel characteristics

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