Steel 65Mn · temper · default condition
Steel 65Mn Annealed
Properties of the Annealed condition, compared with the other 65Mn tempers.
Default stocked condition — softest state for machining, blanking and cold forming before hardening.
What is 65Mn Annealed?
65Mn Annealed is 65Mn in the Annealed temper — default stocked condition — softest state for machining, blanking and cold forming before hardening. 65Mn Annealed has a yield strength of 440 MPa (63.8 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 51% of steel grades. Elongation at break is 16% and the elastic modulus is 206 GPa (29.9 Msi). 65Mn Annealed has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Difficult to weld — 25/100, worse than 77% of steel grades
65Mn Annealed properties
Typical room-temperature values for 65Mn Annealed — 12 properties are specific to this condition; the rest are grade-level values shared by every 65Mn temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
65Mn Annealed has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical14
65Mn Annealed has a yield strength of 440 MPa (63.8 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 51% of steel grades. Elongation at break is 16% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
65Mn Annealed is rated for continuous service to 350°C (662 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical3
65Mn Annealed conducts electricity at 8.5 % IACS, better than 62% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 87% of steel grades.
Sustainability4
Producing a kilogram of 65Mn Annealed takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
65Mn Annealed's machinability is fair (50/100, worse than 53% of steel grades); weldability poor (25/100); formability fair (50/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 65Mn tempers and conditions
65Mn is also supplied in 6 other conditions. The full side-by-side table is on the 65Mn overview.
- AnnealedDefaultDefault stocked condition — softest state for machining, blanking and cold forming before hardening.440 MPa yield · 215 HB
- Hardened & Tempered 50-55 HRCPick for wear-critical thin sections — blades, scrapers, mower and saw teeth — where edge retention beats toughness.1,650 MPa yield · 53 HRC
- Hardened & TemperedStandard spring temper for leaf springs, saw blades and clutch plates — maximum elastic limit with usable toughness.1,400 MPa yield · 46 HRC
- Cold DrawnWork-hardened strip or wire used where hardness is achieved without heat treatment (washers, shims, clips).900 MPa yield · 31 HRC
- Q&THigh-temper condition per GB/T 1222 mechanical test requirement — best strength/toughness balance for structural spring parts.850 MPa yield · 34 HRC
- NormalizedGrain-refining pre-treatment for forgings and heavy bar before final quench and temper.560 MPa yield · 265 HB
- Hot RolledCheapest mill condition for stock that will be re-heat-treated by the fabricator.520 MPa yield · 260 HB
Working with 65Mn Annealed
Is 65Mn easy to machine?
Machine only in the spheroidise-annealed state (≈55 % of 1212); hardened 65Mn needs grinding, CBN or carbide at low feed.
Can 65Mn be welded?
Poor — 0.66 % C gives hard, crack-prone HAZ; if unavoidable use preheat 250–350 °C, low-hydrogen filler and immediate stress-relief/temper, then re-heat-treat.
Can 65Mn be formed, bent or molded?
Blank and bend in the annealed condition with generous radii (≥3 t); hardened spring temper allows only light setting, so form first and heat-treat after; oil quench 810–840 °C, temper 350–420 °C for spring properties.
What surface finishes work on 65Mn?
No anodising — protect with oil, phosphate + oil, black oxide, zinc or Zn-Ni plating (bake to avoid hydrogen embrittlement above 40 HRC); grinds and polishes well when hardened; shot peening markedly raises spring fatigue life.
65Mn chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CGB/T 1222 | 0.62 – 0.7 | 0.66 |
| Si | 0.17 – 0.37 | 0.27 |
| Mnraises hardenability vs 1065 | 0.9 – 1.2 | 1.05 |
| P | ≤ 0.04 | — |
| S | ≤ 0.04 | — |
| Crresidual max | ≤ 0.25 | — |
| Niresidual max | ≤ 0.35 | — |
| Curesidual max | ≤ 0.25 | — |
| Fe | balance | — |
65Mn Annealed — frequently asked
What is 65Mn Annealed used for?
65Mn Annealed is typically used for coil springs, saw blades and springs. In short: medium-carbon spring bar.
What is the yield strength of 65Mn Annealed?
65Mn Annealed has a typical yield strength of 440 MPa (63.8 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 51% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 65Mn Annealed easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine only in the spheroidise-annealed state (≈55 % of 1212); hardened 65Mn needs grinding, CBN or carbide at low feed.
Can 65Mn Annealed be welded?
Not readily — weldability is rated poor (25/100). Poor — 0.66 % C gives hard, crack-prone HAZ; if unavoidable use preheat 250–350 °C, low-hydrogen filler and immediate stress-relief/temper, then re-heat-treat.
What surface finishes work on 65Mn Annealed?
No anodising — protect with oil, phosphate + oil, black oxide, zinc or Zn-Ni plating (bake to avoid hydrogen embrittlement above 40 HRC); grinds and polishes well when hardened; shot peening markedly raises spring fatigue life.
Can 65Mn Annealed be formed, bent or molded?
Blank and bend in the annealed condition with generous radii (≥3 t); hardened spring temper allows only light setting, so form first and heat-treat after; oil quench 810–840 °C, temper 350–420 °C for spring properties.
What is the maximum service temperature of 65Mn Annealed?
65Mn Annealed is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 65Mn Annealed?
Yes — 65Mn Annealed is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- GB/T 1222 Spring steels (2016)
- GB/T 699 Quality carbon structural steels — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.