Steel 1018 · heat-treated state
Steel 1018 Carburized
Properties of the Carburized condition, compared with the other 1018 tempers.
Pick when a wear-resistant hard skin over a tough low-carbon core is needed — gear teeth, bushings, cam followers, pins.
What is 1018 Carburized?
1018 Carburized is 1018 heat treated to Carburized — pick when a wear-resistant hard skin over a tough low-carbon core is needed — gear teeth, bushings, cam followers, pins. 1018 Carburized has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 78% of steel grades. Elongation at break is 15% and the elastic modulus is 205 GPa (29.7 Msi). 1018 Carburized has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 91% of steel grades. It melts at 1,425°C (2,597 °F). HR is the default condition FabDigit quotes; Carburized is available on request or by drawing note.
Advantages
- Readily welded — 95/100, better than 97% of steel grades
- Conducts heat well — 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
Limitations
- Limited formability — 5/100, worse than 99% of steel grades
- Difficult to machine — 15/100, worse than 98% of steel grades
- Low strength — 330 MPa (47.9 ksi), worse than 78% of steel grades
1018 Carburized properties
Typical room-temperature values for 1018 Carburized — 10 properties are specific to this condition; the rest are grade-level values shared by every 1018 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
1018 Carburized has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 91% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
1018 Carburized has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 78% of steel grades. Elongation at break is 15% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1018 Carburized is rated for continuous service to 400°C (752 °F). It conducts heat at 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
1018 Carburized conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 87% of steel grades.
Sustainability4
Producing a kilogram of 1018 Carburized 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
1018 Carburized's machinability is poor (15/100, worse than 98% of steel grades); weldability excellent (95/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 1018 tempers and conditions
1018 is also supplied in 5 other conditions. The full side-by-side table is on the 1018 overview.
- HRDefaultCheapest form; pick for weldments, brackets and parts machined all over where scale and loose tolerance are acceptable.220 MPa yield · 116 HB
- CDPick for shafts, pins and as-supplied-diameter parts needing tight tolerance, straightness and higher yield without heat treatment.370 MPa yield · 126 HB
- CRPick for stamped, bent or laser-cut sheet parts needing a clean, scale-free surface ready for paint or plating.340 MPa yield · 126 HB
- NormalizedPick for uniform fine-grain structure, better toughness and dimensional stability after welding, forging or heavy machining.340 MPa yield · 126 HB
- CarburizedPick when a wear-resistant hard skin over a tough low-carbon core is needed — gear teeth, bushings, cam followers, pins.330 MPa yield · 60 HRC
- AnnealedPick for maximum ductility before deep drawing, severe bending or heavy cold forming, and to remove cold-work stresses.215 MPa yield · 111 HB
Working with 1018 Carburized
Is 1018 easy to machine?
Machines easily but gummy — use positive rake, sharp tools, high speed and generous coolant; cold-drawn stock gives better finish and chip control than hot-rolled.
Can 1018 be welded?
Excellent weldability by all arc, resistance and gas processes with no preheat or PWHT for thin sections; use E7018/ER70S-6 and preheat ~100 °C only in heavy restrained joints.
Can 1018 be formed, bent or molded?
Very good cold formability — bends, roll-forms and stamps readily in annealed/HR condition; cold-drawn bar has lower ductility and may need stress relief before heavy bending.
What surface finishes work on 1018?
Must be protected: zinc/nickel plating, black oxide, manganese phosphate, e-coat or paint; carburize or nitrocarburize for wear surfaces (anodizing not applicable).
1018 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 | 0.15 – 0.2 | 0.18 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.05 | 0.03 |
| Sinot specified in AISI/SAE 1018 bar; 0.15–0.35 typical for killed steel | ≤ 0.35 | 0.2 |
| Fe | balance | — |
1018 Carburized — frequently asked
What is 1018 Carburized used for?
1018 Carburized is typically used for motor shafts, tie rods, machined pins, spacers and bushings, weldment brackets and base plates, carburized gears and cam followers and keyed drive shafts. In short: the standard machining steel.
What is the yield strength of 1018 Carburized?
1018 Carburized has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 78% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 1018 Carburized easy to machine?
Not especially — machinability is rated poor (15/100, worse than 98% of steel grades). Machines easily but gummy — use positive rake, sharp tools, high speed and generous coolant; cold-drawn stock gives better finish and chip control than hot-rolled.
Can 1018 Carburized be welded?
Yes — weldability is rated excellent (95/100). Excellent weldability by all arc, resistance and gas processes with no preheat or PWHT for thin sections; use E7018/ER70S-6 and preheat ~100 °C only in heavy restrained joints.
What surface finishes work on 1018 Carburized?
Must be protected: zinc/nickel plating, black oxide, manganese phosphate, e-coat or paint; carburize or nitrocarburize for wear surfaces (anodizing not applicable).
Can 1018 Carburized be formed, bent or molded?
Very good cold formability — bends, roll-forms and stamps readily in annealed/HR condition; cold-drawn bar has lower ductility and may need stress relief before heavy bending.
What is the maximum service temperature of 1018 Carburized?
1018 Carburized 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 1018-HR and 1018-CD?
HR is the default condition — cheapest form; pick for weldments, brackets and parts machined all over where scale and loose tolerance are acceptable. CD: pick for shafts, pins and as-supplied-diameter parts needing tight tolerance, straightness and higher yield without heat treatment. Yield strength is 220 MPa in HR versus 370 MPa in CD.
Can FabDigit make parts in 1018 Carburized?
Yes — 1018 Carburized is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- 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)
- SAE J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- GB/T 699 (15/20 grades) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Machinery's Handbook, 31st ed. — Industrial Press (2020)
- worldsteel LCI data for steel products — World Steel Association (2023)
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.