Steel 1039-A (Solution annealed)
Temper
AISI/SAE 1039 · UNS G10390
Softest condition, used before heavy machining, deep cold forming or to relieve prior processing stresses.
Values for the A condition
Other 1039 tempers and conditions
1039 is listed in 7 conditions; see the grade overview at 1039.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AThis page Solution annealed | Softest condition, used before heavy machining, deep cold forming or to relieve prior processing stresses. | 320 | 540 | 30 | 149 HB | — |
Normalized | Refines grain and homogenizes forged or hot-rolled bar for uniform machining response and better toughness before hardening. | 380 | 620 | 26 | 187 HB | — |
HRDefault Hot rolled | Lowest-cost general bar for machined parts and weldments where tolerance and surface finish are not critical. | 415 | 620 | 25 | 179 HB | — |
Cold drawn | Choose for close size tolerance, straightness and bright finish with ~30 % higher yield strength; ductility and weldability are reduced by the cold work. | 550 | 655 | 12 | 192 HB | — |
oil quenched, tempered ~590 °C | Tough general-purpose quenched-and-tempered condition for shafts and links in sections up to about 25 mm. | 600 | 790 | 20 | 24 HRC | — |
Induction hardened | Selective surface hardening for wear faces, journals and splines while keeping a tough unhardened core. | 700 | 900 | 14 | 54 HRC | 8.6 % IACS |
oil quenched, tempered ~540 °C | Higher-strength quench-and-temper level for loaded studs, couplings and gear blanks where some ductility is still needed. | 760 | 965 | 16 | 30 HRC | — |
What is 1039-A?
1039-A is 1039 in the A temper — softest condition, used before heavy machining, deep cold forming or to relieve prior processing stresses. 1039-A has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 81% of steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi). 1039-A has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). HR is the default condition FabDigit quotes; A is available on request or by drawing note.
Advantages
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
- Conducts heat well — 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
Limitations
- Low strength — 320 MPa (46.4 ksi), worse than 81% of steel grades
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 78% of steel grades
1039-A properties
Typical room-temperature values for 1039-A; 13 are specific to this condition. Other listed values are 1039 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
1039-A has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
1039-A has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 81% of steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1039-A is rated for continuous service to 400°C (752 °F). It conducts heat at 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
1039-A conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 1039-A takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
1039-A's machinability is fair (54/100, better than 54% of steel grades); weldability fair (50/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1039-A
Is 1039 easy to machine?
Machines readily at ~60 % of 1212; best chip control in the cold-drawn or normalized condition — use carbide, 150–200 m/min, and avoid gummy cuts on fully annealed stock.
Can 1039 be welded?
Weldable with low-hydrogen consumables but CE ≈ 0.55; preheat 150–260 °C, control interpass heat and post-weld temper or stress relieve to avoid HAZ martensite cracking.
Can 1039 be formed, bent or molded?
Hot forge 1150–1230 °C; cold bending only with generous radii (≥2t) and preferably in the annealed condition — cold-drawn bar has limited residual ductility.
What surface finishes work on 1039?
No inherent corrosion resistance: zinc or nickel plate, black oxide, manganese phosphate + oil, or paint; takes a good polish and is suitable for induction/nitrocarburized wear surfaces.
1039 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 1039 (UNS G10390) | 0.37 – 0.44 | 0.4 |
| Mn | 0.7 – 1 | 0.85 |
| P | ≤ 0.04 | — |
| S | ≤ 0.05 | — |
| Fe | balance | — |
1039-A — frequently asked
What is 1039-A used for?
1039-A is typically used for shafting, machine components and studs and bolts. In short: higher ductility medium carbon; induction-hardenable shaft steel; needs preheat for welding.
What is the yield strength of 1039-A?
1039-A has a typical yield strength of 320 MPa (46.4 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 81% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 1039-A easy to machine?
Reasonably — machinability is rated fair (54/100, better than 54% of steel grades). Machines readily at ~60 % of 1212; best chip control in the cold-drawn or normalized condition — use carbide, 150–200 m/min, and avoid gummy cuts on fully annealed stock.
Can 1039-A be welded?
With care — weldability is rated fair (50/100). Weldable with low-hydrogen consumables but CE ≈ 0.55; preheat 150–260 °C, control interpass heat and post-weld temper or stress relieve to avoid HAZ martensite cracking.
What surface finishes work on 1039-A?
No inherent corrosion resistance: zinc or nickel plate, black oxide, manganese phosphate + oil, or paint; takes a good polish and is suitable for induction/nitrocarburized wear surfaces.
Can 1039-A be formed, bent or molded?
Hot forge 1150–1230 °C; cold bending only with generous radii (≥2t) and preferably in the annealed condition — cold-drawn bar has limited residual ductility.
What is the maximum service temperature of 1039-A?
1039-A 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 1039-HR and 1039-IH?
HR is the default condition — lowest-cost general bar for machined parts and weldments where tolerance and surface finish are not critical. IH: selective surface hardening for wear faces, journals and splines while keeping a tough unhardened core. Yield strength is 415 MPa in HR versus 700 MPa in IH.
Sources
- SAE J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- SAE J1397 — Estimated Mechanical Properties and Machinability of Steel Bars — SAE International (2009)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM International (2020)
- ASTM A108 — Steel Bar, Carbon and Alloy, Cold-Finished — ASTM International (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating — ASM International (1991)
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.