SUS304 stainless steel round bars have standard diameter ranges from 5 mm to 300 mm, with common sizes including 10 mm, 16 mm, 25 mm, 50 mm, 100 mm, and 200 mm. JIS G4305:2015 classifies round bars by manufacturing process:
- Hot-rolled bars: Diameters 10–300 mm, with looser tolerances (e.g., ±0.3 mm for 10–30 mm diameters) and a scaled surface finish.
- Cold-drawn bars: Diameters 5–100 mm, with tight tolerances (e.g., ±0.05 mm for 5–10 mm diameters) and a smooth, polished surface (Ra ≤ 1.6 μm).
Diameter tolerance is critical for precision applications-for example, cold-drawn SUS304 bars with 0.05 mm tolerance are used in automotive components, while hot-rolled bars with larger tolerances suit structural uses like handrails. Custom diameters outside the standard range (e.g., 3 mm or 350 mm) can be produced via special orders, though lead times may extend.