SS · stainless
Stainless Steel 430
Ferritic - no nickel, magnetic, and it cuts cleanly without the work-hardening fight of the 300 series. Cheaper than 304 for the same corrosion performance in mild environments.
Quoting this material
- Typical lead time
- 7–12 working days
- Condition
- Annealed
- Achievable finish
- Ra 1.6 µm typical · Ra 0.8 µm best
Machined in-house to your drawing: see the precision CNC machining service and the machine and inspection capability it runs on.
Machinability
Our own 1–10 shop ranking, not a published index: 10 is free-cutting brass C360, 1 is Inconel 718. It ranks how a material behaves on the floor - cycle time, chip control and tool life together. Where a published index exists it is quoted in the note.
Ferritic - no nickel, magnetic, and it cuts cleanly without the work-hardening fight of the 300 series. Cheaper than 304 for the same corrosion performance in mild environments.
Properties as supplied
| Parameter | Value | Unit |
|---|---|---|
| Tensile strength | 450 | MPa |
| Yield strength (0.2%) | 310 | MPa |
| Elongation | 22 | % |
| Hardness | 155 | HB |
| Thermal conductivity | 26.1 | W/m·K |
| Modulus of elasticity | 200 | GPa |
Hardness, tensile and thermal figures are typical published values for the condition stated. Actual mill certificates govern; send the specification with the drawing and we confirm against the certificate before the material is cut.
Condition
Annealed
Heat treatment
Ferritic: not hardenable by heat treatment. Annealing relieves stress and restores ductility after forming or welding.
Achievable surface finish
Ra 1.6 µm
Ra 0.8 µm
A common choice for decoratively visible parts that need to look stainless without the 304 price.
Tooling and cutting parameters
Cutting speed
- 180–300 m/min (carbide)
Feed
- 0.10–0.30 mm/rev turning · 0.08–0.20 mm/tooth milling
Tooling
- Coated or uncoated carbide; it does not need the sharp-edge discipline 304 does
Coolant
- Flood or mist
Starting points for carbide on a rigid setup, not a guarantee. The right numbers depend on the machine, the toolholder and the fixturing - ask and we will say what we would actually run.
Typical applications
- Appliance and trim panels
- Automotive exhaust-adjacent components
- Kitchen and catering equipment
- Fasteners and decorative hardware
- Heat exchanger and burner parts
DFM notes for this grade
- Magnetic, which matters if the part sits near a sensor or a magnetic clamp - this is the difference from 304 that catches people out
- Weldability is limited; in thicker sections it can embrittle at the weld and needs a stabilised grade (430Ti) instead
- Cheaper than 304 and better than mild steel in a mild indoor environment - a sensible substitution for a cost-driven part, not for a washdown area
Questions buyers ask
- Where does 430 stop being good enough?
- Anywhere wet, chlorinated or acidic. It is a mild-environment grade: indoors, dry, non-chemically aggressive. In a washdown area it will show rust staining where the surface has been machined and not passivated.
- Why is 430 magnetic when 304 is not?
- Crystal structure. 430 is ferritic (body-centred cubic), which is magnetic; 304 is austenitic (face-centred cubic), which is essentially non-magnetic. If a design depends on a non-magnetic part, 430 is the wrong material even though it is stainless.