Steel C45-HR (Hot rolled)
Supply condition
EN C45 · AISI/SAE 1045 · JIS S45C · GB 45
Cheapest stock form for weldments and rough-machined parts where strength scatter is acceptable.
Values for the HR condition
Other C45 tempers and conditions
C45 is listed in 10 conditions; see the grade overview at C45.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Spheroidize-annealed C45/1.1061 bar with globular carbides — lowest hardness and best cold-heading/cold-extrusion ductility of the non-hardened conditions. | 330 | 560 | 24 | 175 HB | 10.8 % IACS |
HRThis page Hot rolled | Cheapest stock form for weldments and rough-machined parts where strength scatter is acceptable. | 330 | 585 | 16 | 175 HB | 10 % IACS |
Annealed | Choose for maximum machinability, cold forming or before final hardening. | 350 | 585 | 22 | 165 HB | — |
NormalizedDefault Normalized (≈840–870 °C, air cooled) | Standard stock condition for shafts and machined parts needing uniform medium strength and predictable machining. | 400 | 650 | 17 | 190 HB | — |
Induction hardened | Best choice for wear surfaces — journals, guide rails, splines — keeping a tough normalized or Q&T core. | 450 | 700 | 14 | 57 HRC | 9 % IACS |
Quenched and tempered | Standard delivery condition for loaded shafts, gears and fasteners needing higher yield with retained toughness. | 480 | 700 | 17 | 20 HRC | — |
Spheroidized annealed and cold drawn | Spheroidized then cold-drawn C45/1.1061 bright bar — close tolerances and smooth surface with strength raised by drawing while retaining useful cold-forming ductility. | 500 | 620 | 12 | 195 HB | 10.5 % IACS |
Cold drawn | Pick for close-tolerance bright bar used as-is for shafts, pins and turned parts. | 580 | 700 | 11 | 210 HB | — |
Q&T to 22–26 HRC | Use where toughness and weld-repairability matter more than peak strength (large shafts, pressure parts). | 620 | 830 | 16 | 24 HRC | 9.5 % IACS |
Q&T to 28–32 HRC | Specify when a hardness-controlled, higher-strength core is required for gears, couplings and hydraulic parts. | 760 | 950 | 13 | 30 HRC | — |
What is C45-HR?
C45-HR is C45 supplied in the HR condition — cheapest stock form for weldments and rough-machined parts where strength scatter is acceptable. C45-HR has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 78% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi). C45-HR 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). Normalized is the default condition FabDigit quotes; HR is available on request or by drawing note.
Advantages
- Conducts heat well — 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
Limitations
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 82% of steel grades
- Low strength — 330 MPa (47.9 ksi), worse than 78% of steel grades
C45-HR properties
Typical room-temperature values for C45-HR; 22 are specific to this condition. Other listed values are C45 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
C45-HR 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).
Mechanical16
C45-HR has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 78% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
C45-HR is rated for continuous service to 400°C (752 °F). It conducts heat at 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
C45-HR conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of C45-HR takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
C45-HR's machinability is good (55/100, better than 62% of steel grades); weldability fair (45/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C45-HR
Is C45 easy to machine?
Machines well in +N or +A at ~57% of 1212; use carbide at 120–200 m/min, expect stringy chips and moderate tool wear above 28 HRC.
Can C45 be welded?
Weldable but crack-sensitive (CE≈0.55): preheat 150–250 °C, low-hydrogen consumables, and post-weld stress relief or re-normalizing.
Can C45 be formed, bent or molded?
Hot forge at 1100–850 °C then normalize; cold bending only in annealed condition with generous radii (≥3t).
What surface finishes work on C45?
No anodizing — protect by oxide blackening, zinc phosphate, zinc/Cr plating, nitriding or paint; polishes to a good bright finish for mould plates.
C45 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 10083-2 C45 | 0.42 – 0.5 | 0.45 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.5 – 0.8 | 0.65 |
| P | ≤ 0.03 | |
| S | ≤ 0.04 | |
| CrCr+Mo+Ni ≤ 0.63 | ≤ 0.4 | |
| Ni | ≤ 0.4 | |
| Mo | ≤ 0.1 | |
| Fe | balance |
C45-HR — frequently asked
What is C45-HR used for?
C45-HR is typically used for crankshafts, shafts and industrial bolts. In short: european medium-carbon bar.
What is the yield strength of C45-HR?
C45-HR has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 78% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is C45-HR easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines well in +N or +A at ~57% of 1212; use carbide at 120–200 m/min, expect stringy chips and moderate tool wear above 28 HRC.
Can C45-HR be welded?
With care — weldability is rated fair (45/100). Weldable but crack-sensitive (CE≈0.55): preheat 150–250 °C, low-hydrogen consumables, and post-weld stress relief or re-normalizing.
What surface finishes work on C45-HR?
No anodizing — protect by oxide blackening, zinc phosphate, zinc/Cr plating, nitriding or paint; polishes to a good bright finish for mould plates.
Can C45-HR be formed, bent or molded?
Hot forge at 1100–850 °C then normalize; cold bending only in annealed condition with generous radii (≥3t).
What is the maximum service temperature of C45-HR?
C45-HR is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C45 Normalized and C45-HR?
Normalized is the default condition — standard stock condition for shafts and machined parts needing uniform medium strength and predictable machining. HR: cheapest stock form for weldments and rough-machined parts where strength scatter is acceptable. Yield strength is 400 MPa in Normalized versus 330 MPa in HR.
Can FabDigit make parts in C45-HR?
Yes — C45-HR is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- EN 10083-2 Steels for quenching and tempering — Non-alloy steels — CEN (2006)
- ASTM A29/A29M & SAE J403 (1045) — ASTM / SAE (2020)
- ASM Handbook Vol.1 Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.19 Fatigue and Fracture — ASM International (1996)
- C45 / 1.0503 bar datasheet — Saarstahl / Ovako (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.