Steel 1046-SA (Spheroidize Annealed)
Heat-treated state
AISI/SAE 1046 · UNS G10460
Best condition for cold heading, upsetting or deep machining of this carbon level.
Values for the SA condition
Other 1046 tempers and conditions
1046 is listed in 10 conditions; see the grade overview at 1046.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SAThis page Spheroidize Annealed | Best condition for cold heading, upsetting or deep machining of this carbon level. | 300 | 540 | 24 | 150 HB | 11 % IACS |
HRDefault Hot rolled | Cheapest stock form for parts that will be machined all over or subsequently heat treated. | 310 | 586 | 15 | 170 HB | — |
Solution annealed | Softest condition, used before heavy machining, cold forming or as a stress-relieved starting state. | 310 | 570 | 20 | 163 HB | — |
Normalized | Uniform fine ferrite–pearlite for forgings and pre-machining refinement; better toughness than as-rolled. | 375 | 640 | 17 | 11 HRC | 10.5 % IACS |
Annealed and Cold Drawn | Pick when cold-drawn tolerance is wanted but with softer, lower-residual-stress bar for heavy machining or further cold work. | 495 | 600 | 15 | 179 HB | — |
Cold drawn | Choose for accurate size, bright surface and higher yield strength on as-supplied shafting. | 565 | 655 | 12 | 187 HB | — |
quenched and high-temperature tempered (~620 °C) | Tough, readily machinable condition for general shafts and moderately loaded machine parts. | 620 | 800 | 20 | 24 HRC | — |
Induction hardened | Use where a wear-resistant 55–60 HRC case on a tough core is needed (journals, gear teeth, splines). | 700 | 900 | 14 | 57 HRC | — |
quenched and tempered (~540 °C) | Standard duty condition for shafts, spindles and gear blanks needing strength with useful toughness. | 800 | 965 | 16 | 30 HRC | — |
quenched and tempered (~425 °C) | High-strength condition for heavily loaded pins and shafts; toughness and machinability begin to fall off. | 980 | 1,140 | 13 | 36 HRC | — |
What is 1046-SA?
1046-SA is 1046 heat treated to SA — best condition for cold heading, upsetting or deep machining of this carbon level. 1046-SA has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 86% of steel grades. Elongation at break is 24% and the elastic modulus is 205 GPa (29.7 Msi). 1046-SA 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). HR is the default condition FabDigit quotes; SA is available on request or by drawing note.
Advantages
- High electrical conductivity — 11 % IACS, better than 98% of steel grades
- Easy to machine — 65/100, 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
Limitations
- Low strength — 300 MPa (43.5 ksi), worse than 86% of steel grades
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 78% of steel grades
1046-SA properties
Typical room-temperature values for 1046-SA; 22 are specific to this condition. Other listed values are 1046 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
1046-SA 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
1046-SA has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 86% of steel grades. Elongation at break is 24% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1046-SA 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
1046-SA conducts electricity at 11 % IACS, better than 98% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 1046-SA takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability6
1046-SA's machinability is good (65/100, better than 93% of steel grades); weldability fair (45/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1046-SA
Is 1046 easy to machine?
Machines best at 170–250 HB (annealed/normalized/CD) with carbide tooling and coolant; above 32 HRC use rigid setups and reduced speed, or machine before final temper.
Can 1046 be welded?
Carbon equivalent ~0.6 — preheat 150–260 °C, use low-hydrogen consumables and post-weld stress relief/temper to avoid HAZ martensite cracking.
Can 1046 be formed, bent or molded?
Hot forge 1100–1230 °C then normalize; cold bending is limited — spheroidize anneal first and use generous bend radii.
What surface finishes work on 1046?
No inherent corrosion protection: phosphate + oil, zinc/chrome plating, black oxide or paint; grinds and polishes well after hardening but requires bake-out after plating to prevent hydrogen embrittlement at high hardness.
1046 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 1046, ASTM A29 | 0.43 – 0.5 | 0.46 |
| Mn | 0.7 – 1 | 0.85 |
| Pmax for bar/billet | ≤ 0.04 | 0.02 |
| Smax, non-resulfurized | ≤ 0.05 | 0.03 |
| Sitypical for killed steel; not specified in SAE 10xx chemical limits | 0.15 – 0.35 | 0.25 |
| Fe | balance | — |
1046-SA — frequently asked
What is 1046-SA used for?
1046-SA is typically used for shafts, axles, gears, machine parts and bolts. In short: higher carbon than 1045; C45 / 1.0503 equivalent; hardens to 34–38 HRC.
What is the yield strength of 1046-SA?
1046-SA has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 86% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 1046-SA easy to machine?
Reasonably — machinability is rated good (65/100, better than 93% of steel grades). Machines best at 170–250 HB (annealed/normalized/CD) with carbide tooling and coolant; above 32 HRC use rigid setups and reduced speed, or machine before final temper.
Can 1046-SA be welded?
With care — weldability is rated fair (45/100). Carbon equivalent ~0.6 — preheat 150–260 °C, use low-hydrogen consumables and post-weld stress relief/temper to avoid HAZ martensite cracking.
What surface finishes work on 1046-SA?
No inherent corrosion protection: phosphate + oil, zinc/chrome plating, black oxide or paint; grinds and polishes well after hardening but requires bake-out after plating to prevent hydrogen embrittlement at high hardness.
Can 1046-SA be formed, bent or molded?
Hot forge 1100–1230 °C then normalize; cold bending is limited — spheroidize anneal first and use generous bend radii.
What is the maximum service temperature of 1046-SA?
1046-SA 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 1046-HR and 1046-IH?
HR is the default condition — cheapest stock form for parts that will be machined all over or subsequently heat treated. IH: use where a wear-resistant 55–60 HRC case on a tough core is needed (journals, gear teeth, splines). Yield strength is 310 MPa in HR versus 700 MPa in IH.
Sources
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- SAE J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- EN 10083-2 — Quenched and tempered steels: C45 / 1.0503 — CEN (2006)
- 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)
- Mysteel / SMM (2025)
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.