Steel 55Cr3 Hot Rolled
Finish state
EN 55Cr3
Cheapest supply form for leaf-spring flats and coil-spring bar that will be austenitised by the spring maker.
Values for the Hot Rolled condition
Other 55Cr3 tempers and conditions
55Cr3 is listed in 8 conditions; see the grade overview at 55Cr3.
- AC
- S
- Annealed
- CH
- Hot Rolled
- Normalized
- Cold Drawn
- Q&T
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | 1.7176 annealed to globular carbides — the softest delivery state, used for cold heading, cold extrusion and heavy machining before hardening. | 380 | 640 | 22 | 190 HB | 45 W/m·K |
High Shearability | 1.7176 annealed to a capped hardness so that bar and coil can be cold sheared/cropped cleanly before forming and hardening. | 430 | 730 | 18 | 215 HB | 44 W/m·K |
AnnealedDefault soft (spheroidise) annealed bar | Stock condition for machining, cold forming and pre-heat-treat blanks; hardness capped at 248 HB by EN 10089. | 480 | 800 | 16 | 20 HRC | 7.8 % IACS |
Carburized and hardened | 1.7176 bar supplied heat treated to a specified core hardness band, giving uniform medium-high strength for further machining or induction/case work. | 550 | 870 | 14 | 25 HRC | 43 W/m·K |
Hot RolledThis page as hot rolled bar / flat (mill edge) | Cheapest supply form for leaf-spring flats and coil-spring bar that will be austenitised by the spring maker. | 570 | 950 | 12 | 30 HRC | 7.8 % IACS |
normalised | Used to homogenise forgings and refine grain before hardening; more uniform than as-rolled. | 600 | 950 | 13 | 29 HRC | 7.8 % IACS |
cold drawn / peeled bar (annealed then drawn) | Choose for close diameter tolerance and better surface on torsion-bar and small spring blanks before hardening. | 750 | 950 | 8 | 30 HRC | 7.8 % IACS |
Quenched and tempered | Standard service condition for leaf springs, stabiliser bars and torsion bars: austenitise ~850 °C, oil quench, temper 400–480 °C. | 1,450 | 1,620 | 8 | 46 HRC | — |
What is 55Cr3 Hot Rolled?
55Cr3 Hot Rolled is 55Cr3 supplied in the Hot Rolled condition — cheapest supply form for leaf-spring flats and coil-spring bar that will be austenitised by the spring maker. 55Cr3 Hot Rolled has a yield strength of 570 MPa (82.7 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 74% of steel grades. Elongation at break is 12% and the elastic modulus is 206 GPa (29.9 Msi). 55Cr3 Hot Rolled has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). Annealed is the default condition FabDigit quotes; Hot Rolled is available on request or by drawing note.
Limitations
- Limited ductility — 12%, worse than 84% of steel grades
- Difficult to weld — 20/100, worse than 84% of steel grades
- Low fracture toughness — 65 MPa·√m (59.2 ksi·√in), worse than 75% of steel grades
55Cr3 Hot Rolled properties
Typical room-temperature values for 55Cr3 Hot Rolled; 22 are specific to this condition. Other listed values are 55Cr3 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
55Cr3 Hot Rolled has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical17
55Cr3 Hot Rolled has a yield strength of 570 MPa (82.7 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 74% of steel grades. Elongation at break is 12% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
55Cr3 Hot Rolled is rated for continuous service to 350°C (662 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
55Cr3 Hot Rolled conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental2
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 55Cr3 Hot Rolled takes about 26 MJ of energy and emits 2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
55Cr3 Hot Rolled's machinability is fair (42/100, worse than 73% of steel grades); weldability poor (20/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 55Cr3 Hot Rolled
Is 55Cr3 easy to machine?
Machine in the annealed (+A) state with rigid setups and carbide tooling; at 45–50 HRC only grinding, hard turning with CBN or EDM is practical.
Can 55Cr3 be welded?
Effectively unweldable for structural use (Ceq ≈ 0.85); if unavoidable, preheat 300–350 °C, low-hydrogen consumables and immediate post-weld temper, then re-heat-treat.
Can 55Cr3 be formed, bent or molded?
Coil and bend hot (850–1050 °C) or in the annealed condition; harden from ~840–860 °C in oil and temper 400–480 °C, then stress-relieve set springs at ~250–300 °C.
What surface finishes work on 55Cr3?
Always shot-peen loaded surfaces for fatigue life; protect by phosphate + epoxy/powder paint or zinc-rich coating — avoid acid pickling and standard electroplating without a 190–210 °C hydrogen bake-out.
55Cr3 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 |
|---|---|---|
| CEN 10089 | 0.52 – 0.59 | 0.55 |
| Si | 0.15 – 0.4 | 0.25 |
| Mn | 0.7 – 1 | 0.85 |
| Cr | 0.7 – 1 | 0.85 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
55Cr3 Hot Rolled — frequently asked
What is 55Cr3 Hot Rolled used for?
55Cr3 Hot Rolled is typically used for leaf springs, heavy coil springs, torsion bars, stabiliser (anti-roll) bars, spring clips and retainers and agricultural tine springs. In short: spring chromium bar.
What is the yield strength of 55Cr3 Hot Rolled?
55Cr3 Hot Rolled has a typical yield strength of 570 MPa (82.7 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 74% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 55Cr3 Hot Rolled easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Machine in the annealed (+A) state with rigid setups and carbide tooling; at 45–50 HRC only grinding, hard turning with CBN or EDM is practical.
Can 55Cr3 Hot Rolled be welded?
Not readily — weldability is rated poor (20/100). Effectively unweldable for structural use (Ceq ≈ 0.85); if unavoidable, preheat 300–350 °C, low-hydrogen consumables and immediate post-weld temper, then re-heat-treat.
What surface finishes work on 55Cr3 Hot Rolled?
Always shot-peen loaded surfaces for fatigue life; protect by phosphate + epoxy/powder paint or zinc-rich coating — avoid acid pickling and standard electroplating without a 190–210 °C hydrogen bake-out.
Can 55Cr3 Hot Rolled be formed, bent or molded?
Coil and bend hot (850–1050 °C) or in the annealed condition; harden from ~840–860 °C in oil and temper 400–480 °C, then stress-relieve set springs at ~250–300 °C.
What is the maximum service temperature of 55Cr3 Hot Rolled?
55Cr3 Hot Rolled 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.
What is the difference between 55Cr3 Annealed and 55Cr3-AC?
Annealed is the default condition — stock condition for machining, cold forming and pre-heat-treat blanks; hardness capped at 248 HB by EN 10089. AC: 1.7176 annealed to globular carbides — the softest delivery state, used for cold heading, cold extrusion and heavy machining before hardening. Yield strength is 480 MPa in Annealed versus 380 MPa in AC.
Can FabDigit make parts in 55Cr3 Hot Rolled?
Yes — 55Cr3 Hot Rolled is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- EN 10089 — Hot rolled steels for quenched and tempered springs — CEN (2002)
- SAE J404 / J1397 — Chemical compositions and mechanical properties of SAE alloy steels (5155) — SAE International (2009)
- GB/T 1222 (2016)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Spring Design Manual (HS-795) — SAE International (1996)
- Spring steel bar and flat bar grade data (55Cr3 / 1.7176) — European long-products mills (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.