1018 Carbon Steel (UNS G10180)
The everyday machining steel: low carbon, easily welded and case hardened, cold drawn for a clean finish — for pins, spacers, brackets and non-critical machined parts.
What 1018 is.
1018 is a plain low-carbon steel with about 0.18 percent carbon and a modest manganese addition. It is supplied cold drawn, which gives a smooth surface, tight size tolerance and a useful gain in strength over the hot-rolled bar. It welds and machines well, can be case hardened for wear, and is the default material for machined parts that do not need through-hardened strength.
We machine 1018 pins, spacers, bushings, brackets and general components from cold-finished bar, and supply it plain, zinc plated or black oxide as required.
Chemical composition.
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Carbon | C | 0.15 | 0.20 |
| Manganese | Mn | 0.60 | 0.90 |
| Phosphorus | P | — | 0.040 |
| Sulfur | S | — | 0.050 |
Per SAE J403 / ASTM A29, confirmed by Alro, Eaton Steel Bar and AZoM.
Mechanical properties.
| Condition (¾–1¼ in. round) | Tensile strength, typical (ksi) | Yield strength 0.2% offset, typical (ksi) | Elongation, typical (%) | Reduction of area, typical (%) | Hardness, typical |
|---|---|---|---|---|---|
| Cold drawn | 64 | 54 | 15 | 40 | 126 HB |
| Hot rolled | 58 | 32 | 25 | 50 | — |
Typical values for ¾ to 1¼ in. round bar, confirmed by Online Metals, Capital Steel and AZoM. ASTM A108 sets no mechanical requirements, so order to a stated minimum where one matters.
Specifications that apply.
How 1018 ships from Houston.
- Machined components from certified bar
- Studs, threaded rod and U-bolts
- Hex bolts and cap screws
- Nuts, washers and spacers
- Pins, shafts and bushings
1018 fasteners we make.
Every item is manufactured to your drawing or standard in 1018, imperial or metric, with an EN 10204 3.1 certificate.
What is 1018 steel?
1018 is the most common low-carbon bar steel. Its carbon is too low to through harden significantly, so strength comes from the cold-drawing operation that also gives the bar its bright finish and close tolerance. It is ductile, welds easily, and takes a carburized case well, which makes it the general-purpose choice for machined parts where the load is modest and the price matters.
1018 or 1045?
Use 1018 for parts that are welded, case hardened or lightly loaded. Step up to 1045 when the part needs to be through hardened or must carry more stress in the as-drawn condition; cold-drawn 1045 has about 40 percent more strength than 1018 but welds less easily.
Testing, certification and marking
- Hardness tested per lot; tensile on request or where the specification requires it
- Manufacturer's identification and heat number on every piece where size allows
- EN 10204 3.1 material test report with heat number and chemistry
- PMI verification on request
Recent 1018 jobs.
1020 Carbon Steel (UNS G10200)
A low-carbon steel close to 1018 with lower manganese — weldable, formable and case hardenable, for shafts, pins and general machined parts.
ASTM A108 cold-finished bar · chemistry per ASTM A29 / SAE J4031045 Carbon Steel (UNS G10450)
The medium-carbon workhorse: hardenable by quench and temper, induction hardenable at the surface, strong as drawn — for shafts, axles, studs, gears and hydraulic components.
ASTM A108 / A29 bar1117 Free-Machining Carbon Steel (UNS G11170)
Low-carbon steel with added sulfur and manganese for fast machining and a good carburized case — the screw-machine grade for case-hardened pins, gears and fittings.