Steel 61SiCr7
EN 61SiCr7
61SiCr7 (1.7108, AISI 9261) is a high-carbon silicon-chromium spring steel in the EN 10083 alloy-steel family, using silicon and chromium to give a very high elastic limit and fatigue life.
Reference datasheet — 61SiCr7 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
61SiCr7 tempers and conditions
61SiCr7 is supplied in 7 conditions, soft to hard. +QT is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Choose when maximum cold formability/upsetting or easy machining of this high-carbon grade is required. | 440 | 740 | 20 | 210 HB | — |
Treated for high shearability | Mill condition with controlled soft, uniform structure so bar/coil can be cold sheared to length without cracking. | 470 | 780 | 17 | 20 HRC | 6 % IACS |
Annealed | Standard soft delivery condition for bar and wire that must be cold formed, coiled or machined before hardening. | 500 | 820 | 15 | 235 HB | — |
Supplied with specified (core) hardenability band | Order this when a guaranteed Jominy/hardenability band is needed so heavy bar sections harden through to core. | 520 | 850 | 14 | 23 HRC | 6 % IACS |
Hot rolled | Cheapest mill condition for bar/coil that will be fully re-heat-treated by the spring maker. | 700 | 1,100 | 12 | 31 HRC | 5.8 % IACS |
+QTDefault Quenched and tempered | The service condition for suspension coil springs, torsion bars and leaf springs — peak strength with usable ductility. | 1,550 | 1,750 | 8 | 48 HRC | — |
Hardened | As-quenched martensite — maximum hardness but brittle; an intermediate state that must be tempered before service. | 1,900 | 2,300 | 1 | 63 HRC | — |
Supply forms, finishes and certifications
Ways 61SiCr7 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
OT-WIRE | Oil-tempered Si-Cr valve/suspension spring wire | Supply form |
What is 61SiCr7?
61SiCr7 (1.7108, AISI 9261) is a high-carbon silicon-chromium spring steel in the EN 10083 alloy-steel family, using silicon and chromium to give a very high elastic limit and fatigue life. It is specified for demanding automotive suspension and valve springs and stabilizer bars, supplied as hot-rolled bar, wire and oil-tempered wire in +U, +A, +AC, +S, +CH, +H, +QT and OT-WIRE conditions. Hardened and tempered it gives 1550 MPa yield, 1750 MPa tensile, 8 % elongation and 460 HB (48 HRC), with service capped near 250 °C. It is essentially non-weldable and must be formed soft or hot; 54SiCr6 is the nearest lower-carbon grade. 61SiCr7 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). 61SiCr7 has a yield strength of 1,550 MPa (225 ksi) and a tensile strength of 1,750 MPa (254 ksi) — stronger than 97% of steel grades. Elongation at break is 8% and the elastic modulus is 200 GPa (29 Msi).
What is 61SiCr7 used for?
- suspension springs
- valve springs
- stabilizer bars
Advantages
- High strength — 1,550 MPa (225 ksi), better than 97% of steel grades
Limitations
- Limited ductility — 8%, worse than 95% of steel grades
- Limited formability — 10/100, worse than 95% of steel grades
- Difficult to machine — 25/100, worse than 93% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
- Low fracture toughness — 48 MPa·√m (43.7 ksi·√in), worse than 88% of steel grades
61SiCr7 properties
Typical room-temperature values for 61SiCr7-+QT; bars are the position among steel grades.
Physical3
61SiCr7 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).
Mechanical16
61SiCr7 has a yield strength of 1,550 MPa (225 ksi) and a tensile strength of 1,750 MPa (254 ksi) — stronger than 97% of steel grades. Elongation at break is 8% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
61SiCr7 is rated for continuous service to 250°C (482 °F). It conducts heat at 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
61SiCr7 conducts electricity at 5.5 % IACS, worse than 81% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 61SiCr7 takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
61SiCr7's machinability is poor (25/100, worse than 93% of steel grades); weldability poor (15/100); formability not recommended (10/100).
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. 61SiCr7 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 61SiCr7
Is 61SiCr7 easy to machine?
Machine only in the +A/+AC soft condition with sharp carbide or coated HSS tooling; at 45–52 HRC only grinding or hard turning with CBN is practical.
Can 61SiCr7 be welded?
Essentially not weldable in spring service — high carbon equivalent causes quench cracks; if unavoidable, preheat 300–400 °C and re-heat-treat the whole part.
Can 61SiCr7 be formed, bent or molded?
Hot coil at 850–950 °C or cold coil in annealed/oil-tempered condition, then quench from ~870 °C in oil and temper 400–480 °C for 45–52 HRC; protect against decarburization.
61SiCr7 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 | 0.57 – 0.65 | 0.61 |
| Siraises elastic limit and relaxation resistance | 1.6 – 2 | 1.8 |
| Mn | 0.7 – 1 | 0.85 |
| Crhardenability and temper resistance | 0.2 – 0.4 | 0.3 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on 61SiCr7?
Shot peen (often stress peen) to restore fatigue life after grinding, then phosphate + epoxy powder or zinc-flake coating; avoid acid pickling or electroplating due to 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 61SiCr7 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.7108
- Similar grades
- 9261
How much does 61SiCr7 cost?
61SiCr7 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
61SiCr7 — frequently asked
What is 61SiCr7 used for?
61SiCr7 is typically used for suspension springs, valve springs and stabilizer bars. In short: high-carbon Si-Cr spring steel; very high fatigue life; form soft, harden after.
What is the yield strength of 61SiCr7?
61SiCr7 has a typical yield strength of 1,550 MPa (225 ksi) and a tensile strength of 1,750 MPa (254 ksi) — stronger than 97% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 61SiCr7 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 93% of steel grades). Machine only in the +A/+AC soft condition with sharp carbide or coated HSS tooling; at 45–52 HRC only grinding or hard turning with CBN is practical.
Can 61SiCr7 be welded?
Not readily — weldability is rated poor (15/100). Essentially not weldable in spring service — high carbon equivalent causes quench cracks; if unavoidable, preheat 300–400 °C and re-heat-treat the whole part.
What surface finishes work on 61SiCr7?
Shot peen (often stress peen) to restore fatigue life after grinding, then phosphate + epoxy powder or zinc-flake coating; avoid acid pickling or electroplating due to hydrogen embrittlement.
Can 61SiCr7 be formed, bent or molded?
Hot coil at 850–950 °C or cold coil in annealed/oil-tempered condition, then quench from ~870 °C in oil and temper 400–480 °C for 45–52 HRC; protect against decarburization.
What is the maximum service temperature of 61SiCr7?
61SiCr7 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 61SiCr7 cost?
61SiCr7 is a budget-cost steel ($), 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
- EN 10089 — Hot-rolled steels for quenched and tempered springs — CEN (2002)
- EN 10270-2 — Steel wire for mechanical springs, oil hardened and tempered — CEN (2011)
- EN 10132-4 / EN 10083 delivery-condition designations (+A, +AC, +S, +CH, +H, +QT) — CEN (2003)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys (spring steels) — ASM International (1990)
- ASM Handbook Vol. 19 — Fatigue and Fracture — ASM International (1996)
- GB/T 1222 (60Si2CrA / 61SiCr7 ) — SAC (2016)
- SMM / Mysteel (2025)
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.