Steel VDSiCr
GB VDSiCr
VDSiCr is a silicon-chromium alloyed, oil hardened and tempered valve-spring quality wire to EN 10270-2, used where high stress and relaxation resistance are required.
Reference datasheet — VDSiCr 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 OT condition
VDSiCr tempers and conditions
VDSiCr is supplied in 6 conditions, soft to hard. OT is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
d 5.0–8.0 mm oil hardened and tempered | Larger diameters for suspension, clutch and heavy-duty valve springs; strength drops with section size. | 1,660 | 1,880 | 7 | 53 HRC | 6.6 % IACS |
OT + gas nitrided (+ peened) valve spring | Top-end high-rev valve springs: nitrided case ~700–900 HV gives maximum fatigue and sag resistance at elevated temperature. | 1,780 | 2,000 | 4 | 62 HRC | 6.5 % IACS |
OTDefault Oil hardened and tempered wire, d 2.0–4.0 mm | Standard as-delivered valve-spring wire size range; pick for engine valve springs and high-stress small coil springs. | 1,800 | 2,030 | 6 | 55 HRC | 6.6 % IACS |
OT + stress relieved + shot peened | Choose when fatigue life at high shear stress governs — compressive surface stress raises endurance markedly. | 1,810 | 2,000 | 6 | 57 HRC | 6.6 % IACS |
Stress relieved | Standard post-coiling treatment: restores elastic limit and relaxation resistance after cold coiling. | 1,830 | 2,000 | 6.5 | 54 HRC | 6.6 % IACS |
OT fine wire | Highest strength size class; used for small valve springs, clutch damper and precision springs. | 1,900 | 2,150 | 5 | 57 HRC | 6.6 % IACS |
What is VDSiCr?
VDSiCr is a silicon-chromium alloyed, oil hardened and tempered valve-spring quality wire to EN 10270-2, used where high stress and relaxation resistance are required. Default oil-tempered properties are about 1800 MPa yield, 2030 MPa tensile and 55 HRC, with OT fine and heavy variants plus stress-relieved (SR), shot-peened (SP) and nitrided (NIT) deliveries. Service temperature is limited to about 180 °C, and the wire is unweldable and unmachinable as supplied. VDSiCrV is the next grade up for severe fatigue duty; VDCrV suits hotter but less highly stressed springs. VDSiCr has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,420°C (2,588 °F). VDSiCr has a yield strength of 1,800 MPa (261 ksi) and a tensile strength of 2,030 MPa (294 ksi) — stronger than 99% of steel grades. Elongation at break is 6% and the elastic modulus is 206 GPa (29.9 Msi).
What is VDSiCr used for?
- engine valve springs
- high-cycle fatigue springs
- precision mechanical springs
Advantages
- High strength — 1,800 MPa (261 ksi), better than 99% of steel grades
Limitations
- Difficult to machine — 8/100, worse than 100% of steel grades
- Difficult to weld — 10/100, worse than 99% of steel grades
- Limited service temperature — 180°C (356 °F), worse than 98% of steel grades
- Limited ductility — 6%, worse than 97% of steel grades
- Low fracture toughness — 30 MPa·√m (27.3 ksi·√in), worse than 96% of steel grades
VDSiCr properties
Typical room-temperature values for VDSiCr-OT; bars are the position among steel grades.
Physical3
VDSiCr has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
VDSiCr has a yield strength of 1,800 MPa (261 ksi) and a tensile strength of 2,030 MPa (294 ksi) — stronger than 99% of steel grades. Elongation at break is 6% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
VDSiCr is rated for continuous service to 180°C (356 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical3
VDSiCr conducts electricity at 6.6 % IACS, worse than 76% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of VDSiCr takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 25%.
Manufacturability5
VDSiCr's machinability is not recommended (8/100, worse than 100% of steel grades); weldability not recommended (10/100); formability poor (30/100).
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. VDSiCr is highlighted; hover a dot for its name, or open the interactive family chart.
Working with VDSiCr
Is VDSiCr easy to machine?
Delivered at ~55 HRC — grind or EDM only; ends are ground, not turned, and any nick becomes a fatigue origin.
Can VDSiCr be welded?
Effectively unweldable in service condition; only resistance/friction butt joins with full re-quench-and-temper are acceptable.
Can VDSiCr be formed, bent or molded?
Cold coil on CNC spring machines with generous mandrel ratio (C ≥ 4), then stress relieve 400–430 °C; hot setting/presetting is standard before peening.
VDSiCr 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 | 0.5 – 0.6 | 0.55 |
| Si | 1.2 – 1.6 | 1.4 |
| Mn | 0.5 – 0.9 | 0.7 |
| Cr | 0.5 – 0.8 | 0.65 |
| Pvalve spring quality, low residuals | ≤ 0.02 | 0.01 |
| S | ≤ 0.02 | 0.01 |
| Curesidual | ≤ 0.12 | 0.05 |
| Fe | balance |
What surface finishes work on VDSiCr?
Shot peen (often dual/stress peen), optional gas nitriding, then phosphate + epoxy or zinc-flake coating; avoid acid pickling and electroplating without hydrogen bake-out.
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
How much does VDSiCr cost?
VDSiCr is a standard-cost steel ($$), cheaper than about 71% 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.
VDSiCr — frequently asked
What is VDSiCr used for?
VDSiCr is typically used for engine valve springs, high-cycle fatigue springs and precision mechanical springs. In short: standard high-stress valve wire; strong relaxation resistance; nitridable spring grade.
What is the yield strength of VDSiCr?
VDSiCr has a typical yield strength of 1,800 MPa (261 ksi) and a tensile strength of 2,030 MPa (294 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is VDSiCr easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 100% of steel grades). Delivered at ~55 HRC — grind or EDM only; ends are ground, not turned, and any nick becomes a fatigue origin.
Can VDSiCr be welded?
Not readily — weldability is rated not recommended (10/100). Effectively unweldable in service condition; only resistance/friction butt joins with full re-quench-and-temper are acceptable.
What surface finishes work on VDSiCr?
Shot peen (often dual/stress peen), optional gas nitriding, then phosphate + epoxy or zinc-flake coating; avoid acid pickling and electroplating without hydrogen bake-out.
Can VDSiCr be formed, bent or molded?
Cold coil on CNC spring machines with generous mandrel ratio (C ≥ 4), then stress relieve 400–430 °C; hot setting/presetting is standard before peening.
What is the maximum service temperature of VDSiCr?
VDSiCr is rated for continuous use to about 180°C (356 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between VDSiCr-OT and VDSiCr OT-FINE?
OT is the default condition — standard as-delivered valve-spring wire size range; pick for engine valve springs and high-stress small coil springs. OT-FINE: highest strength size class; used for small valve springs, clutch damper and precision springs. Yield strength is 1,800 MPa in OT versus 1,900 MPa in OT-FINE.
How much does VDSiCr cost?
VDSiCr is a standard-cost steel ($$), cheaper than about 71% 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
- EN 10270-2 Steel wire for mechanical springs — Part 2: Oil hardened and tempered spring steel wire — CEN (2012)
- SAE J157 / SAE 9254 chrome-silicon oil tempered spring wire — SAE International (2018)
- JIS G 3561 SWOSC-V oil tempered Si-Cr valve spring wire — JSA (2013)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (spring steels) — ASM International (1990)
- EN 13906-1 Cylindrical helical springs — design and calculation — CEN (2013)
- Oil tempered Si-Cr valve spring wire datasheets — Suzuki Garphyttan / Kobe Steel (2022)
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.