Steel 1145
AISI/SAE 1145 · UNS G11450
1145 (UNS G11450) is a medium-carbon resulfurized free-machining steel sitting between 1144 and 1146 in composition, with roughly 0.45 % carbon and 0.04–0.07 % sulfur.
Reference datasheet — 1145 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the CD condition
1145 tempers and conditions
1145 is supplied in 9 conditions, soft to hard. CD is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest state for maximum dimensional stability, deep drilling and any limited cold forming or heading. | 310 | 570 | 22 | 163 HB | — |
Hot rolled | Cheapest form for large-diameter turned parts where the as-rolled surface will be machined away. | 325 | 585 | 18 | 170 HB | — |
Normalized | Uniform fine pearlitic structure before machining or hardening; better and more consistent properties than as-rolled. | 375 | 640 | 20 | 187 HB | — |
Cold drawn, stress relieved | Pick when unbalanced machining (keyways, deep slots) would otherwise bow the part after cutting. | 530 | 640 | 15 | 10 HRC | 10 % IACS |
Induction hardened | Use when only bearing or wear surfaces must be hard (55–60 HRC) while the core stays tough and machinable. | 560 | 700 | 12 | 57 HRC | 9 % IACS |
CDDefault Cold drawn | Default stocked condition: straight, size-accurate bright bar with raised strength and good chip control for CNC turning. | 565 | 655 | 12 | 187 HB | — |
quenched and tempered (high temper) | Tough general-purpose hardened condition for shafts and levers that still need drilling and tapping after heat treatment. | 690 | 830 | 17 | 24 HRC | — |
quenched and tempered (medium temper) | Most common hardened spec for medium-duty gears, spindles and hydraulic parts needing strength with some machinability. | 820 | 965 | 15 | 30 HRC | — |
quenched and tempered (low temper) | Highest practical through-hardened strength for this grade; accept reduced toughness and harder machining. | 950 | 1,100 | 12 | 34 HRC | — |
Supply forms, finishes and certifications
Ways 1145 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 1145?
1145 (UNS G11450) is a medium-carbon resulfurized free-machining steel sitting between 1144 and 1146 in composition, with roughly 0.45 % carbon and 0.04–0.07 % sulfur. It is specified for higher-strength turned components such as shafts, axles and fasteners at about 565 MPa yield, 655 MPa tensile, 12 % elongation and 187 HB (90 HRB), with a machinability score of 62 and quench-and-temper conditions from 22 to 36 HRC on file. The trade-offs are low weldability (score 30), limited cold forming (35) and no inherent corrosion resistance. 1144 is the usual substitute where stress-proof bar is stocked. 1145 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F). 1145 has a yield strength of 565 MPa (81.9 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 73% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
What is 1145 used for?
- Shafts
- Axles
- High-strength fasteners
Advantages
- Easy to machine — 62/100, better than 89% of steel grades
- 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
- Limited ductility — 12%, worse than 84% of steel grades
1145 properties
Typical room-temperature values for 1145-CD; bars are the position among steel grades.
Physical3
1145 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F).
Mechanical13
1145 has a yield strength of 565 MPa (81.9 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 73% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1145 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
1145 conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 1145 takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
1145's machinability is good (62/100, better than 89% of steel grades); weldability poor (30/100); 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. 1145 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1145
Is 1145 easy to machine?
Excellent turning/drilling at ~70 % of 1212 — run high surface speeds with sharp carbide, positive rake and good coolant; sulfides give clean chip break and fine finish.
Can 1145 be welded?
Avoid where possible: 0.45 %C plus 0.04–0.07 %S cause hot cracking and hard HAZ; if unavoidable preheat 200–300 °C, use low-hydrogen filler and post-weld stress relief.
Can 1145 be formed, bent or molded?
Only modest cold bending in annealed or hot-rolled condition; hot forge 1100–1230 °C and slow cool or normalize afterwards — do not cold form heavily in the cold-drawn state.
1145 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 |
|---|---|---|
| CSAE/AISI 1145 per SAE J403 / ASTM A29 | 0.42 – 0.49 | 0.46 |
| Mn | 0.7 – 1 | 0.85 |
| P | ≤ 0.04 | 0.02 |
| Sresulfurized for machinability | 0.04 – 0.07 | 0.06 |
| Sinot specified for hot-rolled bar; 0.15–0.35 typical when ordered as killed steel | ≈ 0.22 | 0.22 |
| Fe | balance |
What surface finishes work on 1145?
No inherent corrosion protection — specify black oxide, phosphate + oil, zinc or hard chrome; sulfide stringers can leave micro-pits after polishing or plating.
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).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 1145 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G11450
How much does 1145 cost?
1145 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.
1145 — frequently asked
What is 1145 used for?
1145 is typically used for shafts, axles and high-strength fasteners. In short: highest-carbon 11xx bar; between 1144 and 1146; strength over weldability.
What is the yield strength of 1145?
1145 has a typical yield strength of 565 MPa (81.9 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 73% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 1145 easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Excellent turning/drilling at ~70 % of 1212 — run high surface speeds with sharp carbide, positive rake and good coolant; sulfides give clean chip break and fine finish.
Can 1145 be welded?
Not readily — weldability is rated poor (30/100). Avoid where possible: 0.45 %C plus 0.04–0.07 %S cause hot cracking and hard HAZ; if unavoidable preheat 200–300 °C, use low-hydrogen filler and post-weld stress relief.
What surface finishes work on 1145?
No inherent corrosion protection — specify black oxide, phosphate + oil, zinc or hard chrome; sulfide stringers can leave micro-pits after polishing or plating.
Can 1145 be formed, bent or molded?
Only modest cold bending in annealed or hot-rolled condition; hot forge 1100–1230 °C and slow cool or normalize afterwards — do not cold form heavily in the cold-drawn state.
What is the maximum service temperature of 1145?
1145 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 1145-CD and 1145-A?
CD is the default condition — default stocked condition: straight, size-accurate bright bar with raised strength and good chip control for CNC turning. A: softest state for maximum dimensional stability, deep drilling and any limited cold forming or heading. Yield strength is 565 MPa in CD versus 310 MPa in A.
How much does 1145 cost?
1145 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.
Sources
- SAE J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements — ASTM (2020)
- ASTM A108 — Steel Bar, Carbon and Alloy, Cold-Finished — ASTM (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- GB/T 8731 — (free-cutting structural steel, Y45 comparison) — SAC (2008)
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.