Steel TDSiCr
TDSiCr is a silicon-chromium alloyed, oil hardened and tempered spring steel wire to EN 10270-2, drawn for general mechanical (non-valve) springs that need more strength than plain carbon wire.
Reference datasheet — TDSiCr 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-D1.6-3.0 condition
TDSiCr tempers and conditions
TDSiCr is supplied in 8 conditions, soft to hard. OT-D1.6-3.0 is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
OT, d > 10.0 mm | Heaviest supplied sizes; lowest strength class, best cross-section toughness. | 1,510 | 1,700 | 8 | 49 HRC | 5.7 % IACS |
OT, d = 8.00–10.00 mm | Large suspension / off-highway springs, usually hot- or warm-coiled aids. | 1,580 | 1,780 | 7 | 51 HRC | 5.7 % IACS |
OT, d = 5.00–8.00 mm | Heavier springs where strength drops with section but toughness improves. | 1,660 | 1,870 | 7 | 52 HRC | 5.7 % IACS |
OT, d = 3.00–5.00 mm | Mid-size band for automotive clutch, seat and machinery springs. | 1,740 | 1,960 | 6 | 54 HRC | 5.7 % IACS |
OT-D1.6-3.0Default OT, d = 1.60–3.00 mm | Default stocked size band for general dynamic compression and torsion springs. | 1,830 | 2,060 | 6 | 55 HRC | 5.7 % IACS |
OT + stress relieved after coiling | Standard post-coiling treatment: raises elastic limit and reduces set/relaxation. | 1,880 | 2,020 | 6 | 54 HRC | 5.7 % IACS |
OT + shot peened (and stress relieved) spring | Pick for high-cycle dynamic springs: compressive surface stress greatly raises fatigue life. | 1,880 | 2,020 | 6 | 55 HRC | 5.7 % IACS |
OT, d = 0.50–1.60 mm | Highest strength class; small clutch, latch and instrument springs. | 1,960 | 2,200 | 5 | 57 HRC | 5.7 % IACS |
What is TDSiCr?
TDSiCr is a silicon-chromium alloyed, oil hardened and tempered spring steel wire to EN 10270-2, drawn for general mechanical (non-valve) springs that need more strength than plain carbon wire. In the default oil-tempered condition it gives about 1830 MPa yield and 2060 MPa tensile at 55 HRC, and is supplied as round wire in diameter bands from 0.5 mm to over 10 mm, plus stress-relieved (SR) and shot-peened (SP) deliveries. Maximum service temperature is about 200 °C, and the wire is effectively unweldable and unmachinable at hardness. Where higher fatigue and relaxation resistance are needed, TDSiCrV is the next step up. TDSiCr 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). TDSiCr has a yield strength of 1,830 MPa (265 ksi) and a tensile strength of 2,060 MPa (299 ksi) — stronger than 99% of steel grades. Elongation at break is 6% and the elastic modulus is 206 GPa (29.9 Msi).
What is TDSiCr used for?
- mechanical springs
- clutch springs
- general compression springs
- torsion springs
Advantages
- High strength — 1,830 MPa (265 ksi), better than 99% of steel grades
Limitations
- Difficult to machine — 10/100, worse than 99% of steel grades
- Difficult to weld — 10/100, worse than 99% of steel grades
- Limited ductility — 6%, worse than 97% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Low fracture toughness — 40 MPa·√m (36.4 ksi·√in), worse than 92% of steel grades
TDSiCr properties
Typical room-temperature values for TDSiCr-OT-D1.6-3.0; bars are the position among steel grades.
Physical3
TDSiCr 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).
Mechanical15
TDSiCr has a yield strength of 1,830 MPa (265 ksi) and a tensile strength of 2,060 MPa (299 ksi) — stronger than 99% of steel grades. Elongation at break is 6% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
TDSiCr is rated for continuous service to 200°C (392 °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
TDSiCr conducts electricity at 5.7 % IACS, worse than 80% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of TDSiCr takes about 34 MJ of energy and emits 2.4 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
TDSiCr's machinability is not recommended (10/100, worse than 99% of steel grades); weldability not recommended (10/100); formability fair (35/100).
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. TDSiCr is highlighted; hover a dot for its name, or open the interactive family chart.
Working with TDSiCr
Is TDSiCr easy to machine?
Supplied at 50–57 HRC — effectively not machinable; use grinding, cut-off wheels or ends ground after coiling.
Can TDSiCr be welded?
Not weldable in the spring condition (0.55 %C, martensite cracking and local tempering); use mechanical ends or hooks formed from the wire itself.
Can TDSiCr be formed, bent or molded?
Cold coil with generous mandrel ratio (D/d ≥ 4), then stress relieve at 380–420 °C; avoid nicks and tooling marks that become fatigue initiators.
TDSiCr 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 relaxation resistance | 1.2 – 1.6 | 1.4 |
| Mn | 0.5 – 0.9 | 0.7 |
| Cr | 0.5 – 0.8 | 0.65 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Cu | ≤ 0.2 | |
| Fe | balance |
What surface finishes work on TDSiCr?
Shot peen for dynamic duty, then phosphate + oil, zinc-flake (Dacromet/Geomet) or powder coat; avoid acid pickling/electroplating without bake-out due to hydrogen embrittlement risk.
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 TDSiCr cost?
TDSiCr is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
TDSiCr — frequently asked
What is TDSiCr used for?
TDSiCr is typically used for mechanical springs, clutch springs, general compression springs and torsion springs. In short: stronger than carbon spring wire; general-purpose oil-tempered wire; non-valve spring grade.
What is the yield strength of TDSiCr?
TDSiCr has a typical yield strength of 1,830 MPa (265 ksi) and a tensile strength of 2,060 MPa (299 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is TDSiCr easy to machine?
Not especially — machinability is rated not recommended (10/100, worse than 99% of steel grades). Supplied at 50–57 HRC — effectively not machinable; use grinding, cut-off wheels or ends ground after coiling.
Can TDSiCr be welded?
Not readily — weldability is rated not recommended (10/100). Not weldable in the spring condition (0.55 %C, martensite cracking and local tempering); use mechanical ends or hooks formed from the wire itself.
What surface finishes work on TDSiCr?
Shot peen for dynamic duty, then phosphate + oil, zinc-flake (Dacromet/Geomet) or powder coat; avoid acid pickling/electroplating without bake-out due to hydrogen embrittlement risk.
Can TDSiCr be formed, bent or molded?
Cold coil with generous mandrel ratio (D/d ≥ 4), then stress relieve at 380–420 °C; avoid nicks and tooling marks that become fatigue initiators.
What is the maximum service temperature of TDSiCr?
TDSiCr is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does TDSiCr cost?
TDSiCr is a standard-cost steel ($$), 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)
- EN 13906-1 Cylindrical helical springs — Compression springs (E, G values) — CEN (2013)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys (spring steels) — ASM International (1990)
- Oil tempered Si-Cr spring wire datasheets — Suzuki Garphyttan / Kiswire (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.