Steel 1045
AISI/SAE 1045 · UNS G10450 · EN 1.0503, C45 · JIS S45C · GB 45, 45#
1045 (GB 45#, DIN C45 / 1.0503, JIS S45C) is a plain medium-carbon steel with ~0.45 % C and no deliberate alloying, supplied hot rolled, cold drawn, normalized or quenched-and-tempered.
Values for the CD condition
1045 tempers and conditions
1045 is supplied in 10 conditions, soft to hard. CD 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 |
|---|---|---|---|---|---|---|
Hot rolled | Cheapest form; pick for weldments, large sections and parts that will be fully machined or later heat treated. | 310 | 570 | 16 | 163 HB | — |
Solution annealed | Softest, most ductile and most stable condition — choose for deep machining, cold forming or before hardening. | 310 | 585 | 27 | 163 HB | — |
Normalized | Uniform fine-pearlite structure with balanced strength and toughness; standard pre-condition for gear and shaft blanks and after forging. | 340 | 620 | 22 | 179 HB | — |
Annealed and Cold Drawn | 1045 bar softened by full/sub-critical annealing before cold drawing — lower strength and higher ductility than straight cold-drawn stock, with a bright, close-tolerance surface and good machined finish. | 460 | 600 | 15 | 175 HB | 10.6 % IACS |
Induction hardened | Choose when you need a hard wear surface with a tough unhardened core — shaft journals, cam surfaces, gear teeth, hydraulic rods. | 500 | 700 | 12 | 57 HRC | 9.5 % IACS |
CDDefault Cold drawn | Default stock condition for shafts, pins and machined parts needing straight, on-size bar with higher yield than hot rolled. | 530 | 625 | 12 | 179 HB | — |
quenched and tempered ~600 °C | Pick this quenched and tempered (~600 °C) 22–26 HRC condition for shafts, couplings and bolts where machinability and impact toughness matter more than peak strength. | 570 | 800 | 18 | 24 HRC | — |
quenched and tempered ~540 °C | Most common ordered Q&T hardness band for machine shafts, gear blanks and hydraulic components. | 800 | 1,000 | 15 | 30 HRC | — |
quenched and tempered ~450–480 °C | Higher-strength Q&T band for highly loaded shafts and studs; toughness and machinability start to drop noticeably. | 950 | 1,150 | 12 | 34 HRC | — |
Q&T 205 °C | Maximum hardness/wear condition for thin sections, keys, wear plates and small tooling; brittle and only for sections under ~25 mm (water quench). | 1,300 | 1,600 | 6 | 52 HRC | — |
Supply forms, finishes and certifications
Ways 1045 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 1045?
1045 (GB 45#, DIN C45 / 1.0503, JIS S45C) is a plain medium-carbon steel with ~0.45 % C and no deliberate alloying, supplied hot rolled, cold drawn, normalized or quenched-and-tempered. It is the default general-purpose shafting, gear-blank and machine-part steel because it combines usable strength (600–1100 MPa depending on condition), good machinability and the ability to be through-hardened in thin sections or induction case-hardened. Limits are shallow hardenability (water/oil quench only, sections above ~40 mm do not through-harden), poor corrosion resistance, low notch toughness at sub-zero temperatures, and the need for preheat/post-weld heat treatment when welding. 1045 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). 1045 has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 625 MPa (90.6 ksi) — stronger than 69% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
What is 1045 used for?
- Gears
- Axles
- Shafts
Advantages
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
- Conducts heat well — 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades
Limitations
- Limited ductility — 12%, worse than 84% of steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 82% of steel grades
1045 properties
Typical room-temperature values for 1045-CD; bars are the position among steel grades.
Physical3
1045 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
1045 has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 625 MPa (90.6 ksi) — stronger than 69% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1045 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
1045 conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 1045 takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 35%.
Manufacturability8
1045's machinability is fair (52/100, better than 52% of steel grades); weldability fair (45/100); formability fair (35/100).
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. 1045 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1045
Is 1045 easy to machine?
Machines predictably at ~55 % of 1212 in the 180–220 HB range; use rigid setups, coolant and sharp inserts, and prefer normalized or Q&T ≤32 HRC material for threading and drilling.
Can 1045 be welded?
Weldable with E7018/ER70S-6 but carbon ~0.45 % demands 150–260 °C preheat, low-hydrogen practice, slow cooling and often post-weld stress relief to avoid HAZ cracking.
Can 1045 be formed, bent or molded?
Hot forges easily at 1100–1200 °C; cold bending is limited (bend radii ≥2–3 t) and best done annealed or hot rolled rather than cold drawn.
Manufacturability
The process limits FabDigit's quote engine applies to 1045. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Good52 / 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 / 0.8 µm |
| Hardenable after machining | Yes |
Sheet metal
| Formability | Good35 / 100 |
|---|---|
| Weldability | Good45 / 100 |
1045 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 |
|---|---|---|
| CGB 45: 0.42–0.50; DIN C45: 0.42–0.50 | 0.43 – 0.5 | 0.45 |
| MnGB 45 / JIS S45C: 0.50–0.80 | 0.6 – 0.9 | 0.75 |
| Sinot specified in SAE 1045 bar; GB 45 = 0.17–0.37 | 0.15 – 0.35 | 0.25 |
| Pmax, ASTM A29 | ≤ 0.04 | 0.02 |
| Smax, ASTM A29 | ≤ 0.05 | 0.02 |
| Crresidual limit (GB/T 699) | ≤ 0.25 | |
| Niresidual limit (GB/T 699) | ≤ 0.3 | |
| Curesidual limit (GB/T 699) | ≤ 0.25 | |
| Fe | balance |
What surface finishes work on 1045?
No anodizing; protect with paint, phosphate, black oxide, zinc or hard chrome plating — bare surfaces rust within days in humid air. Takes a good ground/polished finish, best when hardened.
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 1045 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does 1045 cost?
1045 is a budget-cost steel ($), cheaper than about 83% 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.
1045 — frequently asked
What is 1045 used for?
1045 is typically used for gears, axles and shafts. In short: high-strength shafting steel.
What is the yield strength of 1045?
1045 has a typical yield strength of 530 MPa (76.9 ksi) and a tensile strength of 625 MPa (90.6 ksi) — stronger than 69% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 1045 easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machines predictably at ~55 % of 1212 in the 180–220 HB range; use rigid setups, coolant and sharp inserts, and prefer normalized or Q&T ≤32 HRC material for threading and drilling.
Can 1045 be welded?
With care — weldability is rated fair (45/100). Weldable with E7018/ER70S-6 but carbon ~0.45 % demands 150–260 °C preheat, low-hydrogen practice, slow cooling and often post-weld stress relief to avoid HAZ cracking.
What surface finishes work on 1045?
No anodizing; protect with paint, phosphate, black oxide, zinc or hard chrome plating — bare surfaces rust within days in humid air. Takes a good ground/polished finish, best when hardened.
Can 1045 be formed, bent or molded?
Hot forges easily at 1100–1200 °C; cold bending is limited (bend radii ≥2–3 t) and best done annealed or hot rolled rather than cold drawn.
What is the maximum service temperature of 1045?
1045 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 1045-CD and 1045-HR?
CD is the default condition — default stock condition for shafts, pins and machined parts needing straight, on-size bar with higher yield than hot rolled. HR: cheapest form; pick for weldments, large sections and parts that will be fully machined or later heat treated. Yield strength is 530 MPa in CD versus 310 MPa in HR.
How much does 1045 cost?
1045 is a budget-cost steel ($), cheaper than about 83% 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 1045?
Yes — 1045 is available for CNC machining, sheet metal and casting & forging with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A29/A29M Standard Specification for General Requirements for Steel Bars — ASTM (2020)
- ASTM A108 Standard Specification for Steel Bar, Carbon and Alloy, Cold-Finished — ASTM (2018)
- EN 10083-2 Steels for quenching and tempering — C45 / 1.0503 — CEN (2006)
- JIS G4051 Carbon steels for machine structural use (S45C) — JISC (2016)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.16: Machining — ASM International (1989)
- ASM Handbook Vol.19: Fatigue and Fracture — ASM International (1996)
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.