Grade 65Mn Steel High Carbon Spring Steel Properties, Specification, Equivalent

Grade 65Mn High Carbon Spring Steel

65Mn Steel Introduction

65Mn steel is a Chinese GB standard spring steel grade. Its strength, hardness, elasticity and hardenability are higher than that of 65# steel, but it has superheat sensitivity, easy to produce quench crack and temper brittleness. The annealed state has good machinability, and the cold deformation plasticity is low, but the weldability is poor.

65Mn high carbon steel is mainly used in the manufacture of various small-section flat springs, round springs, clockwork, etc. It can also be used to manufacture spring rings, valve springs, shock absorbers, clutch reeds and brake springs.

65Mn Datasheet

Chemical Composition

Chemical Composition %
GradeCSiMnP (≤)S (≤)Cr (≤)Ni (≤)Cu (≤)

65Mn Material Properties

Mechanical Properties
GradeTensile StrengthYield Strength ≥Elongation ≥Reduction in Area ≥Brinell Hardness ≤Density
65Mn9807858.030302 HBW7.85 g/cm3

Notes: Bars with a diameter and side length of not more than 80 mm and flat steels with a thickness of not more than 40 mm.

Heat Treatment Specification

  • Quenching temperature: 830±20 °C (Cooling: oil)
  • Tempering temperature: 540±50 °C
  • Annealing process: annealing temperature 860 ± 10 °C, heat preservation 45-60min, furnace cooling to 750 ± 10 °C, insulation 3-3.5h, after the furnace is cooled to 650-660 °C, and then cooled out of the furnace or put into the insulation pit slow cooling.

65Mn Spring Steel Equivalent

65Mn steel is considered to be equivalent to AISI/SAE 1065, and some people also compare 65Mn with AISI/SAE 1075, 1095, 5160; JIS SK5 (SK85) and Chinese 8Cr13Mov, so I list the chemical composition for your reference.

65Mn vs 1065, 1075, 1095, 5160, SK5 and 8Cr13Mov in chemical composition

Chemical Composition %
GradeCSiMnP (≤)S (≤)CrNi (≤)Cu (≤)MoV
65Mn0.62-0.700.17-0.370.90-1.200.0300.030≤ 0.250.350.25


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