Steel 35SiMn-CD (Cold drawn)
Supply condition
GB 35SiMn
Bright, size-accurate bar for parts machined to near stock size where no further heat treatment is planned.
Values for the CD condition
Other 35SiMn tempers and conditions
35SiMn is listed in 10 conditions; see the grade overview at 35SiMn.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest supply condition (≤229 HBW per GB/T 3077) for deep machining, cold shearing or straightening before final Q&T. | 370 | 640 | 22 | 200 HB | — |
Hot rolled | Cheapest mill condition for stock that will be re-heat-treated after machining or forging. | 470 | 780 | 16 | 235 HB | — |
Normalized | Grain-refining treatment for forgings and for uniform machinability before quench and temper. | 500 | 800 | 17 | 22 HRC | 6 % IACS |
CDThis page Cold drawn | Bright, size-accurate bar for parts machined to near stock size where no further heat treatment is planned. | 650 | 800 | 10 | 22 HRC | 6 % IACS |
QTDefault Quenched and tempered | Use the standard quenched (900 °C, water) and 570 °C tempered condition for shafts, gears, rods and fasteners; it delivers the 780 MPa yield and 950 MPa tensile values quoted in GB/T 3077. | 780 | 950 | 17 | 30 HRC | — |
tempered ~570–600 °C | Tough general-purpose hardness band for large shafts and machined components needing good impact resistance. | 780 | 950 | 17 | 30 HRC | 6 % IACS |
Induction hardened | Use where a tough Q&T core plus a hard, wear- and fatigue-resistant journal or tooth flank is required. | 780 | 950 | 16 | 52 HRC | 6 % IACS |
tempered ~500–540 °C | Higher-strength temper for heavily loaded rods, spindles and high-strength bolts where some toughness is traded for strength. | 980 | 1,150 | 13 | 36 HRC | — |
tempered ~400–450 °C | High-strength/wear condition for pins, wedges and tooling details; watch temper-embrittlement range and notch sensitivity. | 1,150 | 1,350 | 10 | 42 HRC | — |
quenched + tempered 380–430 °C (spring / high-elastic-limit condition) | Choose for flat springs, spring washers and elastic clamps exploiting the high silicon elastic limit. | 1,330 | 1,500 | 8 | 46 HRC | — |
What is 35SiMn-CD?
35SiMn-CD is 35SiMn supplied in the CD condition — bright, size-accurate bar for parts machined to near stock size where no further heat treatment is planned. 35SiMn-CD has a yield strength of 650 MPa (94.3 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 79% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi). 35SiMn-CD 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). QT is the default condition FabDigit quotes; CD is available on request or by drawing note.
Advantages
- High strength — 650 MPa (94.3 ksi), better than 79% of steel grades
Limitations
- Limited ductility — 10%, worse than 91% of steel grades
- Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 90% of steel grades
- Limited formability — 20/100, worse than 80% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
- Low electrical conductivity — 6 % IACS, worse than 78% of steel grades
35SiMn-CD properties
Typical room-temperature values for 35SiMn-CD; 23 are specific to this condition. Other listed values are 35SiMn reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
35SiMn-CD 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).
Mechanical16
35SiMn-CD has a yield strength of 650 MPa (94.3 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 79% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
35SiMn-CD is rated for continuous service to 300°C (572 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
35SiMn-CD conducts electricity at 6 % IACS, worse than 78% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 35SiMn-CD takes about 26 MJ of energy and emits 2.1 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 25%.
Manufacturability8
35SiMn-CD's machinability is fair (52/100, better than 52% of steel grades); weldability poor (30/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 35SiMn-CD
Is 35SiMn easy to machine?
Machine in the annealed (≤229 HBW) or normalised state with carbide tooling; at 30+ HRC use rigid setups, reduced feeds and coolant — silicon makes chips abrasive on tool flanks.
Can 35SiMn be welded?
Poor weldability (CE ≈ 0.8–0.9): preheat 250–350 °C, use low-hydrogen consumables, keep interpass temperature and temper immediately after welding to avoid cold cracking.
Can 35SiMn be formed, bent or molded?
Hot forge/roll 1150 → 850 °C with slow cooling or immediate annealing; cold bending only in the annealed state with generous radii — Q&T material cracks.
What surface finishes work on 35SiMn?
No corrosion resistance: protect with phosphate + oil, black oxide, zinc or Dacromet coating; hard chrome or induction hardening plus grinding for wear surfaces (bake after plating to avoid hydrogen embrittlement).
35SiMn 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 |
|---|---|---|
| C | 0.32 – 0.4 | 0.36 |
| Siprimary strengthening/elastic-limit element | 1.1 – 1.4 | 1.25 |
| Mn | 1.1 – 1.4 | 1.25 |
| Crresidual | ≤ 0.3 | 0.1 |
| Niresidual | ≤ 0.3 | 0.1 |
| Curesidual | ≤ 0.25 | 0.1 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.02 |
| Fe | balance | — |
35SiMn-CD — frequently asked
What is 35SiMn-CD used for?
35SiMn-CD is typically used for shafts, springs and gears. In short: silicon-manganese spring steel; chromium-free hardenable bar; 9260 cross-reference.
What is the yield strength of 35SiMn-CD?
35SiMn-CD has a typical yield strength of 650 MPa (94.3 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 79% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 35SiMn-CD easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machine in the annealed (≤229 HBW) or normalised state with carbide tooling; at 30+ HRC use rigid setups, reduced feeds and coolant — silicon makes chips abrasive on tool flanks.
Can 35SiMn-CD be welded?
Not readily — weldability is rated poor (30/100). Poor weldability (CE ≈ 0.8–0.9): preheat 250–350 °C, use low-hydrogen consumables, keep interpass temperature and temper immediately after welding to avoid cold cracking.
What surface finishes work on 35SiMn-CD?
No corrosion resistance: protect with phosphate + oil, black oxide, zinc or Dacromet coating; hard chrome or induction hardening plus grinding for wear surfaces (bake after plating to avoid hydrogen embrittlement).
Can 35SiMn-CD be formed, bent or molded?
Hot forge/roll 1150 → 850 °C with slow cooling or immediate annealing; cold bending only in the annealed state with generous radii — Q&T material cracks.
What is the maximum service temperature of 35SiMn-CD?
35SiMn-CD is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 35SiMn-QT and 35SiMn-A?
QT is the default condition — use the standard quenched (900 °C, water) and 570 °C tempered condition for shafts, gears, rods and fasteners; it delivers the 780 MPa yield and 950 MPa tensile values quoted in GB/T 3077. A: softest supply condition (≤229 HBW per GB/T 3077) for deep machining, cold shearing or straightening before final Q&T. Yield strength is 780 MPa in QT versus 370 MPa in A.
Sources
- GB/T 699 / GB/T 702 bar dimensional and delivery requirements — SAC (2015)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 4 — Heat Treating — ASM International (1991)
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.