Steel 6118
AISI/SAE 6118 · UNS G61180
6118 is a chromium-vanadium case-hardening steel (AISI/SAE 6118, UNS G61180) in which vanadium provides grain refinement and good hardenability for precision small parts.
Reference datasheet — 6118 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 A condition
6118 tempers and conditions
6118 is supplied in 7 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault 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?
6118 is a chromium-vanadium case-hardening steel (AISI/SAE 6118, UNS G61180) in which vanadium provides grain refinement and good hardenability for precision small parts. It is chosen for small gears, hand tools and fasteners where dimensional stability after carburizing matters, and is available hot-rolled, annealed, normalized, normalized-and-tempered, cold-drawn, quenched-and-tempered to 25–32 HRC, or case-hardened to 58–62 HRC. Default-condition values are 315 MPa yield, 470 MPa tensile, 31 % elongation and 137 HB (76 HRB), with machinability 58 and formability 60. Vanadium carbides increase tool wear slightly, and the steel offers no corrosion resistance without plating or phosphating. 6118 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). 6118 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).
What is 6118 used for?
- small gears
- hand tools
- fasteners
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 properties
Typical room-temperature values for 6118-A; bars are the position among steel grades.
Physical3
6118 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 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 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 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 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'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. 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. 6118 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 6118
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.
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 |
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.
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 6118 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G61180
How much does 6118 cost?
6118 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.
6118 — frequently asked
What is 6118 used for?
6118 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?
6118 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 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 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?
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 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?
6118 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.
How much does 6118 cost?
6118 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 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; 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.