Steel S45C
JIS S45C · AISI/SAE 1045 · EN C45, 1.0503 · GB 45
S45C is the JIS medium-carbon steel equivalent to AISI 1045 and to C45 / 1.0503 of EN 10083-2, unalloyed and strengthened by quenching and tempering or induction hardening.
Values for the Normalized condition
S45C tempers and conditions
S45C is supplied in 8 conditions, soft to hard. Normalized is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Pick for maximum softness before heavy cold forming, deep drilling or re-hardening. | 310 | 570 | 24 | 163 HB | — |
Hot rolled | Cheapest stock form for weldments and rough machined parts where dimensional and property scatter is acceptable. | 340 | 590 | 18 | 179 HB | — |
NormalizedDefault 840–870 °C air cooled | Default stocked condition: uniform fine pearlitic structure, predictable machining and a sound base for later induction or through hardening. | 380 | 620 | 20 | 187 HB | — |
Quenched and tempered | General strengthened condition per JIS/GB for shafts, gears and connecting parts needing ≥690 MPa with good toughness. | 550 | 750 | 18 | 22 HRC | — |
Induction hardened | Choose when a wear-resistant 50–58 HRC skin (0.5–3 mm case) is needed on a tough normalized or Q&T core, e.g. shaft journals and guide rails. | 550 | 750 | 15 | 55 HRC | — |
Cold drawn | Choose for close tolerance, bright surface shafting used with little or no machining; note residual stress and lower ductility. | 600 | 700 | 12 | 207 HB | — |
quenched and tempered to 28–32 HRC | Mould plate / gear blank condition: highest strength still comfortably machinable with carbide tooling. | 750 | 950 | 14 | 30 HRC | — |
quenched and tempered at low temperature | Use for wear parts and small-section shafts where strength beats toughness; grinding usually needed after heat treat. | 950 | 1,150 | 11 | 37 HRC | — |
Supply forms, finishes and certifications
Ways S45C is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
TGP | Turned, Ground and Polished bar | Surface finish |
What is S45C?
S45C is the JIS medium-carbon steel equivalent to AISI 1045 and to C45 / 1.0503 of EN 10083-2, unalloyed and strengthened by quenching and tempering or induction hardening. Normalized bar gives 380 MPa yield, 620 MPa tensile, 20 % elongation and about 187 HB, and it is widely available as hot-rolled, cold-drawn and TGP bar, plate and sheet for shafts, crankshafts and industrial bolts. Weldability is limited by a carbon equivalent near 0.6, there is no corrosion resistance, and 4140 or 42CrMo is the step up when higher through-hardened strength is needed. S45C 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). S45C has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 68% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi).
What is S45C used for?
- Crankshafts
- Shafts
- Industrial bolts
Advantages
- High electrical conductivity — 10.7 % IACS, better than 91% of steel grades
- Conducts heat well — 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades
Limitations
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 86% of steel grades
S45C properties
Typical room-temperature values for S45C-Normalized; bars are the position among steel grades.
Physical3
S45C 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
S45C has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 68% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
S45C 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
S45C conducts electricity at 10.7 % IACS, better than 91% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of S45C takes about 26 MJ of energy and emits 2.1 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 30%.
Manufacturability8
S45C's machinability is good (58/100, better than 75% 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. S45C is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S45C
Is S45C easy to machine?
Good turning/milling at ~57 % of 1212; best chip control at 170–230 HB, use rigid setups and coolant above 300 HB, expect abrasive tool wear from pearlite.
Can S45C be welded?
Weldable but carbon-equivalent ≈0.6: preheat 150–250 °C, low-hydrogen consumables (E7018/ER70S-6) and post-weld stress relief or normalizing to avoid HAZ martensite cracking.
Can S45C be formed, bent or molded?
Hot forge 1100–1200 °C then normalize; cold bending is limited (generous bend radii, anneal first), and cold-drawn bar should be stress-relieved before heavy machining to control distortion.
Manufacturability
The process limits FabDigit's quote engine applies to S45C. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Better58 / 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 |
S45C 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 |
|---|---|---|
| CJIS G4051 S45C | 0.42 – 0.48 | 0.45 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.03 | |
| S | ≤ 0.04 | |
| Curesidual max | ≤ 0.3 | |
| Niresidual max; Ni+Cr ≤ 0.35 | ≤ 0.2 | |
| Crresidual max | ≤ 0.2 | |
| Fe | balance |
What surface finishes work on S45C?
No anodizing; protect by black oxide, phosphate, zinc/nickel or hard-chrome plating, paint or oil — surfaces flash-rust within hours of grinding.
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 S45C in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does S45C cost?
S45C 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.
S45C — frequently asked
What is S45C used for?
S45C is typically used for crankshafts, shafts and industrial bolts. In short: normalized Japanese carbon bar.
What is the yield strength of S45C?
S45C has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 68% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is S45C easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Good turning/milling at ~57 % of 1212; best chip control at 170–230 HB, use rigid setups and coolant above 300 HB, expect abrasive tool wear from pearlite.
Can S45C be welded?
With care — weldability is rated fair (45/100). Weldable but carbon-equivalent ≈0.6: preheat 150–250 °C, low-hydrogen consumables (E7018/ER70S-6) and post-weld stress relief or normalizing to avoid HAZ martensite cracking.
What surface finishes work on S45C?
No anodizing; protect by black oxide, phosphate, zinc/nickel or hard-chrome plating, paint or oil — surfaces flash-rust within hours of grinding.
Can S45C be formed, bent or molded?
Hot forge 1100–1200 °C then normalize; cold bending is limited (generous bend radii, anneal first), and cold-drawn bar should be stress-relieved before heavy machining to control distortion.
What is the maximum service temperature of S45C?
S45C 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 S45C Normalized and S45C-CD?
Normalized is the default condition — default stocked condition: uniform fine pearlitic structure, predictable machining and a sound base for later induction or through hardening. CD: choose for close tolerance, bright surface shafting used with little or no machining; note residual stress and lower ductility. Yield strength is 380 MPa in Normalized versus 600 MPa in CD.
How much does S45C cost?
S45C 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 S45C?
Yes — S45C 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
- JIS G 4051 — Carbon steels for machine structural use — JISC (2016)
- EN 10083-2 — Non-alloy quality steels C45 (1.0503) — CEN (2006)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Metals Reference Book / machinability ratings — ASM International (1993)
- Carbon steel LCI datasets (embodied energy/carbon) — worldsteel (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.