Steel 35SiMn
GB 35SiMn
35SiMn is a silicon–manganese structural and spring steel (cross-referenced to 9260) used where chromium-bearing hardenable grades are to be avoided.
Reference datasheet — 35SiMn is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the QT condition
35SiMn tempers and conditions
35SiMn is supplied in 10 conditions, soft to hard. QT is the default FabDigit quotes; the values on this page are for it.
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 |
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?
35SiMn is a silicon–manganese structural and spring steel (cross-referenced to 9260) used where chromium-bearing hardenable grades are to be avoided. Conditions on file run from hot-rolled and annealed through cold-drawn to quench-and-temper at 28–32, 34–38 and 40–45 HRC, a spring temper and induction hardening; default Q&T values are 780 MPa yield, 950 MPa tensile, 17 % elongation and 285 HB (30 HRC) with service to 400 °C. Common forms are hot-rolled and cold-drawn bar and wire for shafts, gears and springs. Weldability is poor (30/100) at CE ≈ 0.8–0.9 and there is no corrosion resistance; 4140 or 5160 are the nearest alternatives. 35SiMn 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). 35SiMn has a yield strength of 780 MPa (113 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 86% of steel grades. Elongation at break is 17% and the elastic modulus is 210 GPa (30.5 Msi).
What is 35SiMn used for?
- shafts
- springs
- gears
Advantages
- High strength — 780 MPa (113 ksi), better than 86% of steel grades
Limitations
- Low electrical conductivity — 6 % IACS, worse than 78% of steel grades
35SiMn properties
Typical room-temperature values for 35SiMn-QT; bars are the position among steel grades.
Physical3
35SiMn 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 has a yield strength of 780 MPa (113 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 86% of steel grades. Elongation at break is 17% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
35SiMn is rated for continuous service to 400°C (752 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
35SiMn 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 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's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (30/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. 35SiMn is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 35SiMn
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.
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 |
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).
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 35SiMn in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- 9260
How much does 35SiMn cost?
35SiMn is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
35SiMn — frequently asked
What is 35SiMn used for?
35SiMn 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?
35SiMn has a typical yield strength of 780 MPa (113 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 35SiMn easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% 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 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?
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 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?
35SiMn is rated for continuous use to about 400°C (752 °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.
How much does 35SiMn cost?
35SiMn is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.