Steel 1139 NORM
Heat-treated state
AISI/SAE 1139 · UNS G11390
NORM = normalized
Refines forging/rolling structure and gives uniform mid-range strength before final machining.
Values for the NORM condition
Other 1139 tempers and conditions
1139 is listed in 9 conditions; see the grade overview at 1139.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot rolled | Lowest-cost form for parts that will be fully machined or later heat treated. | 345 | 620 | 16 | 11 HRC | 10 % IACS |
Annealed | Softest condition, used before severe machining or when maximum dimensional stability matters. | 345 | 570 | 22 | 8 HRC | 10.5 % IACS |
NORMThis page Normalized | Refines forging/rolling structure and gives uniform mid-range strength before final machining. | 380 | 655 | 20 | 11 HRC | 10 % IACS |
Cold Drawn, Stress Relieved | Choose when heavy asymmetric machining would otherwise cause the part to bow. | 530 | 640 | 14 | 10 HRC | 10 % IACS |
CDDefault Cold drawn | Standard stocked condition: best size tolerance, straightness and chip control for screw-machine work. | 565 | 655 | 12 | 192 HB | — |
Induction hardened | Pick for wear surfaces and bearing journals where the machined core toughness is retained. | 570 | 700 | 11 | 54 HRC | 9.5 % IACS |
oil quenched from ~845 °C, tempered high | Tough, readily machinable strength level for shafts and studs with moderate loading. | 660 | 830 | 17 | 24 HRC | 9.5 % IACS |
oil quenched, tempered ~540 °C | Common through-hardened level for higher-load shafts, pins and threaded fasteners. | 780 | 950 | 15 | 30 HRC | — |
oil quenched, tempered ~455 °C | Highest practical through-hardened level; accept reduced toughness and machinability. | 930 | 1,120 | 12 | 36 HRC | 9 % IACS |
What is 1139 NORM?
1139 NORM is 1139 heat treated to NORM — refines forging/rolling structure and gives uniform mid-range strength before final machining. 1139 NORM has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 68% of steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi). 1139 NORM 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). CD is the default condition FabDigit quotes; NORM is available on request or by drawing note.
Advantages
- Easy to machine — 70/100, better than 96% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% 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
- Hard to polish — 40/100, worse than 96% of steel grades
1139 NORM properties
Typical room-temperature values for 1139 NORM; 23 are specific to this condition. Other listed values are 1139 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
1139 NORM 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).
Mechanical13
1139 NORM has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 68% of steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1139 NORM 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
1139 NORM 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 1139 NORM takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
1139 NORM's machinability is very good (70/100, better than 96% of steel grades); weldability poor (32/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1139 NORM
Is 1139 easy to machine?
Excellent chip breaking from MnS; run 20–30% higher surface speed than 1045, carbide inserts, positive rake, light sulfurized oil or coolant.
Can 1139 be welded?
Not recommended for structural welds — high S plus ~0.40 C promotes hot cracking and hard HAZ; if welded, preheat 200–300 °C, low-hydrogen consumables and post-weld stress relief.
Can 1139 be formed, bent or molded?
Poor cold formability, especially transverse; hot forge 1150–1230 °C and finish above 900 °C, then normalize.
What surface finishes work on 1139?
No anodizing; protect with zinc or zinc-nickel plating, black oxide, phosphate-and-oil, or paint. Sulfide stringers limit mirror polish and can leave micro-pits after plating.
1139 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 J403 / ASTM A29 heat analysis | 0.35 – 0.43 | 0.39 |
| Mn | 1.35 – 1.65 | 1.5 |
| P | ≤ 0.04 | 0.02 |
| Sresulfurized for machinability | 0.13 – 0.2 | 0.16 |
| Sinot normally specified for resulfurized grades | ≤ 0.1 | 0.05 |
| Fe | balance | — |
1139 NORM — frequently asked
What is 1139 NORM used for?
1139 NORM is typically used for shafts, studs and bolts. In short: free-machining 1140 equivalent; heat-treatable to 38 HRC; poor weldability by design.
What is the yield strength of 1139 NORM?
1139 NORM has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 68% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 1139 NORM easy to machine?
Yes — machinability is rated very good (70/100, better than 96% of steel grades). Excellent chip breaking from MnS; run 20–30% higher surface speed than 1045, carbide inserts, positive rake, light sulfurized oil or coolant.
Can 1139 NORM be welded?
Not readily — weldability is rated poor (32/100). Not recommended for structural welds — high S plus ~0.40 C promotes hot cracking and hard HAZ; if welded, preheat 200–300 °C, low-hydrogen consumables and post-weld stress relief.
What surface finishes work on 1139 NORM?
No anodizing; protect with zinc or zinc-nickel plating, black oxide, phosphate-and-oil, or paint. Sulfide stringers limit mirror polish and can leave micro-pits after plating.
Can 1139 NORM be formed, bent or molded?
Poor cold formability, especially transverse; hot forge 1150–1230 °C and finish above 900 °C, then normalize.
What is the maximum service temperature of 1139 NORM?
1139 NORM 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 1139-CD and 1139-HR?
CD is the default condition — standard stocked condition: best size tolerance, straightness and chip control for screw-machine work. HR: lowest-cost form for parts that will be fully machined or later heat treated. Yield strength is 565 MPa in CD versus 345 MPa in HR.
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 (Y40Mn comparable grade) — SAC (2008)
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.