1020 low-carbon steel is one of the most widely used mild steels in general engineering. Its balanced combination of weldability, toughness and cost makes it ideal for shafts, bushings, mounting brackets and a host of everyday machine components. When paired with precision CNC machining, 1020 steel can be shaped into tight-tolerance parts that are ready for carburizing, black-oxide finishing or straightforward assembly.
Why 1020 Low-Carbon Steel CNC Parts?
Predictable Properties
With roughly 0.20 % carbon and modest manganese, 1020 steel offers a yield strength around 210 MPa in the hot-rolled state while remaining highly ductile. That makes it forgiving during forming and minimizes cracking during welding.
Excellent Machinability
On a machinability index where 1212 free-cutting steel is 100 %, 1020 scores about 65 %. In practice this means moderate cutting forces, long tool life with P-grade carbide, and clean chips when flood-cooled.
Easy to Heat-Treat
Although classified as a mild steel, 1020 responds well to surface-hardening processes. A shallow carburize followed by oil quench can lift case hardness above HRC 55 while preserving a tough core.
Cost Advantage
Compared with alloy grades such as 4140, 1020 typically costs 20–30 % less per kilogram, allowing greater design freedom for non-critical strength members.
Heat-Treatment and Surface-Finishing Options
| Process | Typical Goal | Resulting Benefits |
| Carburizing @ 920 °C, 0.8 mm case | Wear-resistant surface, tough core | Gear blanks, cams |
| Black oxide (traditional “bluing”) | Light corrosion protection, low glare | Hand tools, fixtures |
| Phosphate + oil | Anti-galling, paint base | Fasteners, brackets |
| Zinc plating | Cosmetic bright finish, rust delay | Consumer assemblies |
When parts must combine wear resistance with cost efficiency, carburized 1020 is hard to beat; only critical, high-load applications usually justify a switch to 1045 or alloy steels.
Applications We Machine at CNC Rapid
- Conveyor and packaging shaft pins held to ±0.01 mm run-out
- Weldable flanges with pre-machined bevels for pipeline spools
- Hydraulic cylinder clevises that receive black oxide after machining
- Automated welding fixtures where low-carbon steel prevents cracking in tack-welds
- Our multi-axis mills and lathes machine bar, tube or custom blanks up to Ø 450 mm and 1 m in length.
Design Tips
- Keep wall thicknesses above 3 mm to avoid warping during case hardening.
- Specify radii ≥ 0.8 mm in internal corners to match common end-mill sizes.
- Call out ISO Fit class for shafts and bores; h9/g6 is typical for press fits in mild steel.
Why Choose CNC Rapid for 1020 steel parts
1020 low-carbon steel is the workhorse material that balances price, ease of machining and post-processing flexibility. Whether you need a single prototype or a short-run production lot, CNC Rapid can turn your STEP or IGES file into finished parts—often within 10–14 calendar days plus 3–4 days DHL worldwide transit.
We invite you to take advantage of our Metal & Plastic parts machining service, ideal for both prototypes and production needs. To receive a personalized quote, simply visit our website to get quote or reach out directly to our team at [email protected] with details of your project.
For the most accurate and speedy quote, kindly include the following in your communication:
- Part Name
- 3D Drawing
- Quantity
- Material
- Tolerance Range
- Surface Finish
We appreciate your interest and look forward to serving your machining needs. Thank you for your time!
