Steel 52SiCrNi5 +CH
Heat-treated state
EN 52SiCrNi5
+CH = treated to specified core hardness
Order this when a guaranteed core hardness / through-hardness band (≈40–48 HRC) with higher toughness is needed rather than peak spring strength.
Values for the +CH condition
Other 52SiCrNi5 tempers and conditions
52SiCrNi5 is listed in 9 conditions; see the grade overview at 52SiCrNi5.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Pick when the bar or wire must be cold headed, cold drawn or heavily machined before hardening. | 420 | 700 | 22 | 215 HB | — |
Annealed | Softest general delivery condition for bar/wire that will be machined or hot formed before hardening. | 450 | 750 | 18 | 230 HB | — |
Treated for high shearability | Bar condition with structure/hardness controlled so blanks can be cold sheared without cracking or excessive burr. | 500 | 800 | 15 | 22 HRC | 7.5 % IACS |
Hot rolled | Cheapest mill delivery for leaf-spring flats and bar that will be fully heat treated by the spring maker. | 550 | 900 | 12 | 27 HRC | 7.5 % IACS |
Normalized | Used to refine grain and homogenize forgings before final hardening; not a service condition for springs. | 600 | 950 | 12 | 29 HRC | 7.5 % IACS |
Cold drawn | Bright drawn bar/wire with close tolerance and clean surface, for coiling or machining prior to hardening. | 760 | 900 | 8 | 27 HRC | 7 % IACS |
+CHThis page Treated to specified core hardness | Order this when a guaranteed core hardness / through-hardness band (≈40–48 HRC) with higher toughness is needed rather than peak spring strength. | 1,300 | 1,500 | 10 | 45 HRC | — |
+QTDefault Quenched and tempered | Standard in-service condition for coil, leaf and torsion springs: peak strength and fatigue life with acceptable toughness. | 1,700 | 1,900 | 7 | 52 HRC | — |
Hardened | As-quenched martensite — maximum hardness but brittle; an intermediate state that must be tempered before service. | 1,900 | 2,300 | 1 | 62 HRC | — |
What is 52SiCrNi5 +CH?
52SiCrNi5 +CH is 52SiCrNi5 heat treated to +CH — order this when a guaranteed core hardness / through-hardness band (≈40–48 HRC) with higher toughness is needed rather than peak spring strength. 52SiCrNi5 +CH has a yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,500 MPa (218 ksi) — stronger than 95% of steel grades. Elongation at break is 10% and the elastic modulus is 206 GPa (29.9 Msi). 52SiCrNi5 +CH 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). +QT is the default condition FabDigit quotes; +CH is available on request or by drawing note.
Advantages
- High strength — 1,300 MPa (189 ksi), better than 95% of steel grades
Limitations
- Difficult to weld — 12/100, worse than 96% of steel grades
- Low fracture toughness — 33 MPa·√m (30 ksi·√in), worse than 95% of steel grades
- Limited formability — 12/100, worse than 92% of steel grades
- Limited ductility — 10%, worse than 91% of steel grades
- Difficult to machine — 28/100, worse than 91% of steel grades
52SiCrNi5 +CH properties
Typical room-temperature values for 52SiCrNi5 +CH; 14 are specific to this condition. Other listed values are 52SiCrNi5 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
52SiCrNi5 +CH 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
52SiCrNi5 +CH has a yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,500 MPa (218 ksi) — stronger than 95% of steel grades. Elongation at break is 10% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
52SiCrNi5 +CH is rated for continuous service to 350°C (662 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
52SiCrNi5 +CH conducts electricity at 7 % IACS, worse than 74% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 52SiCrNi5 +CH takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 30%.
Manufacturability7
52SiCrNi5 +CH's machinability is poor (28/100, worse than 91% of steel grades); weldability not recommended (12/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 52SiCrNi5 +CH
Is 52SiCrNi5 easy to machine?
Machine in +A/+AC condition (≈215–248 HB) with carbide tooling; at 50+ HRC only grinding, hard turning with CBN or EDM are practical.
Can 52SiCrNi5 be welded?
Effectively non-weldable at 0.5 %C — if unavoidable, preheat 300–400 °C, low-hydrogen process and immediate post-weld temper; expect loss of spring properties in the HAZ.
Can 52SiCrNi5 be formed, bent or molded?
Cold coil or cold form in the annealed/spheroidized state then harden; hot form at 950–1050 °C, austenitize 860–880 °C, oil quench, temper 400–480 °C for 48–54 HRC.
What surface finishes work on 52SiCrNi5?
Shot peen and stress relieve springs to boost fatigue life; protect with phosphate+oil, zinc-flake or epoxy — avoid acid pickling/electroplating without post-bake to prevent hydrogen embrittlement.
52SiCrNi5 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 | 0.49 – 0.56 | 0.52 |
| Siraises yield ratio and relaxation resistance | 1.2 – 1.5 | 1.35 |
| Mn | 0.7 – 1 | 0.85 |
| Cr | 0.7 – 1 | 0.85 |
| Niadded for toughness and hardenability vs 52SiCr6 | 0.5 – 0.7 | 0.6 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
52SiCrNi5 +CH — frequently asked
What is 52SiCrNi5 +CH used for?
52SiCrNi5 +CH is typically used for heavy-duty springs, stabilizer bars and torsion bars. In short: nickel-toughened spring steel; highest strength of the Si-Cr springs; shock-load spring service.
What is the yield strength of 52SiCrNi5 +CH?
52SiCrNi5 +CH has a typical yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,500 MPa (218 ksi) — stronger than 95% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 52SiCrNi5 +CH easy to machine?
Not especially — machinability is rated poor (28/100, worse than 91% of steel grades). Machine in +A/+AC condition (≈215–248 HB) with carbide tooling; at 50+ HRC only grinding, hard turning with CBN or EDM are practical.
Can 52SiCrNi5 +CH be welded?
Not readily — weldability is rated not recommended (12/100). Effectively non-weldable at 0.5 %C — if unavoidable, preheat 300–400 °C, low-hydrogen process and immediate post-weld temper; expect loss of spring properties in the HAZ.
What surface finishes work on 52SiCrNi5 +CH?
Shot peen and stress relieve springs to boost fatigue life; protect with phosphate+oil, zinc-flake or epoxy — avoid acid pickling/electroplating without post-bake to prevent hydrogen embrittlement.
Can 52SiCrNi5 +CH be formed, bent or molded?
Cold coil or cold form in the annealed/spheroidized state then harden; hot form at 950–1050 °C, austenitize 860–880 °C, oil quench, temper 400–480 °C for 48–54 HRC.
What is the maximum service temperature of 52SiCrNi5 +CH?
52SiCrNi5 +CH is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10089 — Hot rolled steels for quenched and tempered springs — CEN (2002)
- EN 10083-1/-3 — Steels for quenching and tempering (delivery condition symbols +A, +AC, +S, +QT) — CEN (2006)
- 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)
- European spring steel bar datasheets (52SiCr6 / 52SiCrNi5, 1.7117) — various mills (2022)
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.