Steel 6118-A (Solution annealed)
Temper · default condition
AISI/SAE 6118 · UNS G61180
Default stock condition: softest, best machinability before carburizing.
Values for the A condition
Other 6118 tempers and conditions
6118 is listed in 7 conditions; see the grade overview at 6118.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefaultThis page Solution annealed | Default stock condition: softest, best machinability before carburizing. | 315 | 470 | 31 | 137 HB | — |
Hot rolled | Cheapest mill condition for parts that will be fully re-heat-treated after machining. | 350 | 540 | 24 | 160 HB | 7.5 % IACS |
Normalized and tempered | Stress-relieved normalized bar for dimensionally stable machining of larger sections. | 350 | 520 | 24 | 160 HB | 7.5 % IACS |
Normalized | Uniform fine-grained structure and better core toughness before carburizing or final machining. | 370 | 550 | 21 | 170 HB | 7.5 % IACS |
Cold drawn | Close-tolerance, higher-strength bar for pins and shafts machined with minimal stock removal. | 520 | 620 | 15 | 187 HB | — |
through hardened and tempered (thin sections) | Direct-quenched and high-temperature tempered small sections where no case is required. | 720 | 900 | 17 | 29 HRC | — |
Carburized, quenched & tempered | Final service condition for gears, cams and splines: hard wear-resistant case with tough low-carbon core. | 750 | 1,000 | 12 | 60 HRC | — |
What is 6118-A?
6118-A is 6118 in the A temper — default stock condition: softest, best machinability before carburizing. 6118-A has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 82% of steel grades. Elongation at break is 31% and the elastic modulus is 205 GPa (29.7 Msi). 6118-A 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).
Advantages
- Ductile — tolerates forming and impact — 31%, better than 94% of steel grades
Limitations
- Low strength — 315 MPa (45.7 ksi), worse than 82% of steel grades
6118-A properties
Typical room-temperature values for 6118-A; 11 are specific to this condition. Other listed values are 6118 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
6118-A 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).
Mechanical15
6118-A has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 82% of steel grades. Elongation at break is 31% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
6118-A is rated for continuous service to 400°C (752 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
6118-A conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 6118-A takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
6118-A's machinability is good (58/100, better than 75% of steel grades); weldability good (65/100); formability good (60/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 6118-A
Is 6118 easy to machine?
Machine in the annealed or cold-drawn condition (~60 % of 1212); vanadium carbides accelerate tool wear slightly, so use coated carbide and rigid setups, and finish before carburizing.
Can 6118 be welded?
Weldable in the low-carbon annealed/normalized state with low-hydrogen consumables, 150–250 °C preheat and post-weld stress relief; do not weld carburized or hardened parts.
Can 6118 be formed, bent or molded?
Good cold formability when annealed (bending, upsetting, thread rolling); hot work 1100–1200 °C, finish above 900 °C and normalize afterwards to restore fine grain.
What surface finishes work on 6118?
No anodizing — protect with zinc or nickel plating, phosphate + oil, or black oxide; grind or hone carburized surfaces after hardening and bake plated parts to avoid hydrogen embrittlement.
6118 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 |
|---|---|---|
| C | 0.16 – 0.21 | 0.18 |
| Mn | 0.5 – 0.7 | 0.6 |
| Si | 0.15 – 0.35 | 0.25 |
| Cr | 0.5 – 0.7 | 0.6 |
| Vgrain refiner; some specs list 0.10 min only | 0.1 – 0.15 | 0.12 |
| P | ≤ 0.04 | — |
| S | ≤ 0.04 | — |
| Fe | balance | — |
6118-A — frequently asked
What is 6118-A used for?
6118-A is typically used for small gears, hand tools and fasteners. In short: fine-grain Cr-V carburizer; stable for precision parts; case to 58–62 HRC.
What is the yield strength of 6118-A?
6118-A has a typical yield strength of 315 MPa (45.7 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 82% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 6118-A easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machine in the annealed or cold-drawn condition (~60 % of 1212); vanadium carbides accelerate tool wear slightly, so use coated carbide and rigid setups, and finish before carburizing.
Can 6118-A be welded?
Yes — weldability is rated good (65/100). Weldable in the low-carbon annealed/normalized state with low-hydrogen consumables, 150–250 °C preheat and post-weld stress relief; do not weld carburized or hardened parts.
What surface finishes work on 6118-A?
No anodizing — protect with zinc or nickel plating, phosphate + oil, or black oxide; grind or hone carburized surfaces after hardening and bake plated parts to avoid hydrogen embrittlement.
Can 6118-A be formed, bent or molded?
Good cold formability when annealed (bending, upsetting, thread rolling); hot work 1100–1200 °C, finish above 900 °C and normalize afterwards to restore fine grain.
What is the maximum service temperature of 6118-A?
6118-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 6118-A and 6118 CH58-62?
A is the default condition — default stock condition: softest, best machinability before carburizing. CH58-62: final service condition for gears, cams and splines: hard wear-resistant case with tough low-carbon core. Yield strength is 315 MPa in A versus 750 MPa in CH58-62.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- SAE J1268 / J406 — Hardenability and Hardenability Bands for Alloy Steels — SAE International (2019)
- ASTM A29/A29M — General Requirements for Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 4A — Steel Heat Treating Fundamentals and Processes (carburizing) — ASM International (2013)
- Machinery's Handbook, 31st ed. (machinability ratings) — Industrial Press (2020)
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.