SAE 1010 vs SAE 1018: differences explained
SAE 1010 vs 1018: 0.10 % carbon against 0.18 %, and the gap decides everything — forming and welding against machining and case hardening.
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Overview
Two low-carbon steels separated by eight hundredths of a percent of carbon, and the market treats them as different products. 1010 is a forming steel: sheet, strip, wire and welded tube, chosen because it bends, draws and welds without argument. 1018 is the bar stock of the machine shop: the default for turned parts, shafts, pins and anything that will be carburised.
The carbon does the work in both directions. More carbon in 1018 means higher strength, chips that break instead of tearing, and enough carbon to take a case. Less carbon in 1010 means better elongation, a cleaner weld and less springback.
One caution before substituting: the product form matters as much as the grade. Cold-drawn 1018 and hot-rolled 1018 differ more from each other than 1018 differs from 1010 in the same condition.
SAE 1010 vs SAE 1018 side by side
| Property | SAE 1010 | SAE 1018 |
|---|---|---|
| Standard | SAE J403 / ASTM A29 | SAE J403 / ASTM A29 |
| Carbon | 0.08–0.13 % | 0.15–0.20 % |
| Manganese | 0.30–0.60 % | 0.60–0.90 % |
| Max P / S | 0.040 / 0.050 % | 0.040 / 0.050 % |
| Yield, hot rolled | ≈ 180 MPa | ≈ 220 MPa |
| Tensile, hot rolled | ≈ 325 MPa | ≈ 400 MPa |
| Yield, cold drawn | ≈ 305 MPa | ≈ 370 MPa |
| Tensile, cold drawn | ≈ 365 MPa | ≈ 440 MPa |
| Elongation, cold drawn | ≈ 20 % | ≈ 15 % |
| Hardness, cold drawn | ≈ 105 HB | ≈ 126 HB |
| Machinability (B1112 = 100) | ≈ 55 % | ≈ 78 % |
| Weldability | Excellent, no preheat | Very good, no preheat below 20 mm |
| Case hardening | Possible, soft core | The standard carburising grade of its class |
| Cold forming | Very good — deep draws, tight bends | Moderate — springs back and cracks sooner |
| Usual product form | Sheet, strip, wire, welded tube | Round, square and flat bar; cold-drawn and turned |
| EN equivalent | C10 / 1.0301 | C15 / 1.0401 (near; C15E for a closer match) |
| JIS equivalent | S10C | S20C (S15C for the low end) |
| Heat treatment response | Little — too little carbon to harden through | Case hardens well; will not through-harden |
| Where it fails | Anything needing strength or a clean machined finish | Anything needing a deep draw or a tight bend |
| Typical price | Base commodity | Small premium as cold-drawn bar; similar as coil |
Which should you choose?
1018 for anything held in a chuck, 1010 for anything held in a die. The machine shop answer is 1018 almost every time: it turns cleanly, holds a tolerance after cold drawing, and takes a carburised case for a wear surface. The press and tube shop answer is 1010, because carbon is exactly what makes a part crack at the radius and spring away from the form.
Neither is a structural specification in the European sense — for a load calculation the grade to name is S235JR or S355JR, not a SAE carbon number.
- Deep-drawn and stamped parts where elongation decides whether the blank survives
- Welded tube and roll-formed profile, where consistent springback sets the mill
- Wire, fasteners formed cold, and chain
- Parts welded thin-to-thin where the lowest carbon gives the cleanest joint
- Enamelling and heavy surface work, where a soft substrate is an advantage
- Turned, milled and drilled parts where chip formation and surface finish matter
- Shafts, pins, spacers and bushings from cold-drawn bar
- Components to be carburised for a hard case over a tough core
- Jigs and fixtures needing a little more strength than mild sheet offers
- Anywhere a cold-drawn tolerance saves a machining pass
Frequently asked questions
What is the difference between 1010 and 1018 steel?
Carbon and manganese: 1010 carries 0.08–0.13 % C with 0.30–0.60 % Mn, 1018 carries 0.15–0.20 % C with 0.60–0.90 % Mn. That gives 1018 roughly 20 % more strength and much better machinability, while 1010 forms and welds more easily.
Is 1018 stronger than 1010?
Yes, by roughly 20 %. In the cold-drawn condition 1018 runs about 370 MPa yield and 440 MPa tensile against about 305 and 365 MPa for 1010. Both figures shift downward in the hot-rolled condition, so the product form has to be compared like for like.
Which machines better, 1010 or 1018?
1018, clearly — about 78 % on the B1112 scale against roughly 55 % for 1010. The extra carbon and manganese give chips that break instead of tearing, which is why 1018 is the default bar stock in a machine shop and 1010 is not.
Can 1010 be case hardened?
It can be carburised, but the core stays soft because there is not enough carbon to support it. Where a hard case over a load-bearing core is needed, 1018 is the grade of this pair to use, and 8620 or 16MnCr5 above it if the core has to carry more.
What is the European equivalent of 1018?
C15 (1.0401) is the usual match, with C15E (1.1141) closer on the controlled-sulphur side. It is an equivalence rather than an identity: the SAE and EN systems specify different sulphur ranges and different delivery conditions, so the certificate should be read rather than assumed.
Which welds better?
1010, marginally. Both are well below the carbon level that needs preheat, so in practice either welds with standard procedures; 1010's lower carbon simply gives a slightly softer heat-affected zone, which matters on thin sheet welded to thin sheet.
Related comparisons
Verified against SAE J403 · ASTM A29/A29M. Last checked: October 2026.