Steel C45
EN C45 · AISI/SAE 1045 · JIS S45C · GB 45
C45 (1.1061, equivalent to AISI 1045, JIS S45C and GB 45) is a medium-carbon quality steel at about 0.45% C, with higher strength and hardening capability than C35 and normally supplied heat treated.
Values for the Normalized condition
C45 tempers and conditions
C45 is supplied in 10 conditions, soft to hard. Normalized is the default FabDigit quotes; the values on this page are for it.
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 |
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?
C45 (1.1061, equivalent to AISI 1045, JIS S45C and GB 45) is a medium-carbon quality steel at about 0.45% C, with higher strength and hardening capability than C35 and normally supplied heat treated. Normalized bar gives around 400 MPa yield, 650 MPa tensile, 17% elongation and 190 HB, with annealed, quenched-and-tempered and induction-hardened conditions on file for shafts, gears and machine parts up to about 400 °C service. Weldability is limited by a carbon equivalent near 0.55 and corrosion resistance is nil; use a lower-carbon grade such as C35 where welding dominates. C45 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). C45 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 60% of steel grades. Elongation at break is 17% and the elastic modulus is 210 GPa (30.5 Msi).
What is C45 used for?
- Crankshafts
- Shafts
- Industrial bolts
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 — 50 MPa·√m (45.5 ksi·√in), worse than 86% of steel grades
C45 properties
Typical room-temperature values for C45-Normalized; bars are the position among steel grades.
Physical3
C45 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 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 60% of steel grades. Elongation at break is 17% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
C45 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 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 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's machinability is good (55/100, better than 62% of steel grades); weldability fair (45/100); formability fair (40/100).
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. C45 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C45
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).
Manufacturability
The process limits FabDigit's quote engine applies to C45. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Better55 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better40 / 100 |
|---|---|
| Weldability | Better45 / 100 |
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 |
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.
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).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel C45 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does C45 cost?
C45 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C45 — frequently asked
What is C45 used for?
C45 is typically used for crankshafts, shafts and industrial bolts. In short: european medium-carbon bar.
What is the yield strength of C45?
C45 has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is C45 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines well in +N or +A at ~57% of 1212; use carbide at 120–200 m/min, expect stringy chips and moderate tool wear above 28 HRC.
Can C45 be welded?
With care — weldability is rated fair (45/100). Weldable but crack-sensitive (CE≈0.55): preheat 150–250 °C, low-hydrogen consumables, and post-weld stress relief or re-normalizing.
What surface finishes work on C45?
No anodizing — protect by oxide blackening, zinc phosphate, zinc/Cr plating, nitriding or paint; polishes to a good bright finish for mould plates.
Can C45 be formed, bent or molded?
Hot forge at 1100–850 °C then normalize; cold bending only in annealed condition with generous radii (≥3t).
What is the maximum service temperature of C45?
C45 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C45 Normalized and C45-HR?
Normalized is the default condition — standard stock condition for shafts and machined parts needing uniform medium strength and predictable machining. HR: cheapest stock form for weldments and rough-machined parts where strength scatter is acceptable. Yield strength is 400 MPa in Normalized versus 330 MPa in HR.
How much does C45 cost?
C45 is a budget-cost steel ($), 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.
Can FabDigit make parts in C45?
Yes — C45 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; 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.