Steel TDSiCrV-SP
Finish state
SP = stress relieved + shot peened
Choose for maximum fatigue life in dynamically loaded suspension/clutch springs; compressive surface layer.
Values for the SP condition
Other TDSiCrV tempers and conditions
TDSiCrV is listed in 7 conditions; see the grade overview at TDSiCrV.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
OT, wire dia 10.00–17.00 mm | Largest supplied sections for heavy-duty vehicle and machinery springs; lowest tensile band. | 1,510 | 1,710 | 9 | 50 HRC | 5 % IACS |
OT, wire dia 6.00–10.00 mm | Heavy wire for large compression springs where hardenability limits peak tensile. | 1,600 | 1,810 | 9 | 52 HRC | 5 % IACS |
OT, wire dia 4.00–6.00 mm | Mid-heavy section for suspension, clutch and industrial machinery springs. | 1,700 | 1,920 | 8 | 54 HRC | 5 % IACS |
OT-D2.0-4.0Default OT, wire dia 2.00–4.00 mm | Most commonly stocked diameter band for high-duty compression and torsion springs. | 1,780 | 2,010 | 7 | 55 HRC | 5 % IACS |
Stress relieved | Standard post-coiling condition of a finished spring: restores elastic limit and reduces set/relaxation. | 1,820 | 1,960 | 7 | 54 HRC | 5 % IACS |
SPThis page Stress relieved + shot peened | Choose for maximum fatigue life in dynamically loaded suspension/clutch springs; compressive surface layer. | 1,820 | 1,960 | 6 | 55 HRC | 5 % IACS |
OT, wire dia 0.50–2.00 mm | Fine wire for small high-stress clutch, brake and mechanism springs; highest tensile band. | 1,880 | 2,120 | 6 | 57 HRC | 5 % IACS |
What is TDSiCrV-SP?
TDSiCrV-SP is TDSiCrV supplied in the SP condition — choose for maximum fatigue life in dynamically loaded suspension/clutch springs; compressive surface layer. TDSiCrV-SP has a yield strength of 1,820 MPa (264 ksi) and a tensile strength of 1,960 MPa (284 ksi) — stronger than 99% of steel grades. Elongation at break is 6% and the elastic modulus is 206 GPa (29.9 Msi). TDSiCrV-SP has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,420°C (2,588 °F). OT-D2.0-4.0 is the default condition FabDigit quotes; SP is available on request or by drawing note.
Advantages
- High strength — 1,820 MPa (264 ksi), better than 99% of steel grades
Limitations
- Low fracture toughness — 21 MPa·√m (19.1 ksi·√in), worse than 99% of steel grades
- Difficult to machine — 10/100, worse than 99% of steel grades
- Difficult to weld — 8/100, 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
TDSiCrV-SP properties
Typical room-temperature values for TDSiCrV-SP; 21 are specific to this condition. Other listed values are TDSiCrV reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
TDSiCrV-SP has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
TDSiCrV-SP has a yield strength of 1,820 MPa (264 ksi) and a tensile strength of 1,960 MPa (284 ksi) — stronger than 99% of steel grades. Elongation at break is 6% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
TDSiCrV-SP is rated for continuous service to 180°C (356 °F). It conducts heat at 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
TDSiCrV-SP conducts electricity at 5 % IACS, worse than 82% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of TDSiCrV-SP takes about 33 MJ of energy and emits 2.4 kg of CO₂ — more than 76% of steel grades. Typical recycled content is 20%.
Manufacturability6
TDSiCrV-SP's machinability is not recommended (10/100, worse than 99% of steel grades); weldability not recommended (8/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with TDSiCrV-SP
Is TDSiCrV easy to machine?
Supplied at ~50–58 HRC — essentially not machinable; use abrasive cutoff, grinding or carbide/CBN tooling for end grinding only.
Can TDSiCrV be welded?
Not weldable in service condition: high C+Si gives hard, crack-prone HAZ and destroys the tempered structure; use mechanical ends or hooks formed by coiling.
Can TDSiCrV be formed, bent or molded?
Cold-coil only, with generous spring-back allowance (C/d ≥ 4 recommended); always stress-relieve at ~380–430 °C after coiling, then pre-set and shot peen for dynamic duty.
What surface finishes work on TDSiCrV?
Phosphate + oil, zinc flake (Dacromet/Geomet) or epoxy coating are preferred; avoid electroplating or bake at 190–220 °C ≥4 h immediately afterwards to prevent hydrogen embrittlement.
TDSiCrV 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 |
| Siraises elastic limit and relaxation resistance | 1.2 – 1.6 | 1.4 |
| Mn | 0.5 – 0.9 | 0.7 |
| Cr | 0.5 – 0.8 | 0.65 |
| Vgrain refinement + stable carbides, improves fatigue and temperature stability | 0.1 – 0.2 | 0.15 |
| P | ≤ 0.02 | — |
| S | ≤ 0.02 | — |
| Cu | ≤ 0.12 | — |
| Fe | balance | — |
TDSiCrV-SP — frequently asked
What is TDSiCrV-SP used for?
TDSiCrV-SP is typically used for mechanical springs, high-fatigue compression springs, automotive suspension springs and general industrial springs. In short: higher fatigue life than TDSiCr; vanadium-modified spring wire; best non-valve OT grade.
What is the yield strength of TDSiCrV-SP?
TDSiCrV-SP has a typical yield strength of 1,820 MPa (264 ksi) and a tensile strength of 1,960 MPa (284 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is TDSiCrV-SP easy to machine?
Not especially — machinability is rated not recommended (10/100, worse than 99% of steel grades). Supplied at ~50–58 HRC — essentially not machinable; use abrasive cutoff, grinding or carbide/CBN tooling for end grinding only.
Can TDSiCrV-SP be welded?
Not readily — weldability is rated not recommended (8/100). Not weldable in service condition: high C+Si gives hard, crack-prone HAZ and destroys the tempered structure; use mechanical ends or hooks formed by coiling.
What surface finishes work on TDSiCrV-SP?
Phosphate + oil, zinc flake (Dacromet/Geomet) or epoxy coating are preferred; avoid electroplating or bake at 190–220 °C ≥4 h immediately afterwards to prevent hydrogen embrittlement.
Can TDSiCrV-SP be formed, bent or molded?
Cold-coil only, with generous spring-back allowance (C/d ≥ 4 recommended); always stress-relieve at ~380–430 °C after coiling, then pre-set and shot peen for dynamic duty.
What is the maximum service temperature of TDSiCrV-SP?
TDSiCrV-SP 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 TDSiCrV OT-D2.0-4.0 and TDSiCrV-SR?
OT-D2.0-4.0 is the default condition — most commonly stocked diameter band for high-duty compression and torsion springs. SR: standard post-coiling condition of a finished spring: restores elastic limit and reduces set/relaxation. Yield strength is 1,780 MPa in OT-D2.0-4.0 versus 1,820 MPa in SR.
Sources
- EN 10270-2 Steel wire for mechanical springs — Part 2: Oil hardened and tempered spring steel wire — CEN (2012)
- EN 13906-1 Cylindrical helical springs made from round wire and bar — Compression springs — CEN (2013)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (spring steels) — ASM International (1990)
- Oil tempered Si-Cr-V spring wire datasheets (Garphyttan / Suzuki Garphyttan, Kobe Steel, Nippon Steel) — various producers (2023)
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.