SK3, SK5SK85 (SK5) carbon tool steel Standard: JIS G4401 ● Features and Scope: After quenching and tempering with high hardness and wear resistance, but low hot hardness, hardenability poor, low deformation, ductility and strength . Used as a need to have a high hardness and wear resistance of a variety of tools, such as the shape of the mold and punch a simple tool metal cutting, drilling tools, woodworking cutter, countersink drill, axes, chisels, hand saws vertical and fitter assembly tools, dies and other minor rivet tool. ● Chemical Composition: Carbon C: 0.80 ~ 0.90 Si Si: 0.10-0.35 Mn Mn: 0.10-0.50 sulfur S: ≤0.030 phosphorus P: ≤0.030 chromium Cr: to allow the residual content ≤0.25, ≤0.10 (bath quenching steel manufacturing lead ) Ni: to allow the residual content of ≤0.20, ≤0.12 (the manufacture of lead wire quenching bath) Cu: to allow the residual content ≤0.30, ≤0.20 (bath quenching steel manufacturing lead time) Note: to allow the residual content of Cr + Ni + Cu≤ 0.40 (bath quenching steel manufacturing lead time) ● mechanical Properties: Hardness: annealing, ≤187HB, indentation diameter ≥4.40mm; quenching, ≥62HRC ● heat treatment and microstructure specifications: heat Treatment Specification: Sample quenching 780 ~ 820 ℃, water-cooled. ● Delivery status: Delivery of steel in the annealed condition. By mutual agreement, can not annealed state delivery