the guide distinguishes rough castings from finished castings and lists surface-treatment options by steel family. Roughness values are Ra in micrometres (μm).
Surface roughness (Ra, μm)
| Casting condition | Weight and wall-thickness conditions in the diagram | Ra (μm) |
|---|---|---|
| Rough casting | Weight >5 kg; main wall thickness >12 mm | 3.2–6.3 |
| Rough casting | Weight <5 kg; main wall thickness <12 mm | 1.6–3.2 |
| Finished casting | No additional condition printed | 0.8–1.6 |
Carbon steel and low alloy steel
Blacking, zinc plating, chrome plating and nickel plating.
Stainless steel
Tumbling, hand dull polishing, mirror polishing, electrolytic polishing and passivation treatment.
All steel castings
Sandblasting, including glass bead blasting, corundum-sand blasting and quartz-sand blasting.
Design notes
- the guide lists greater-than and less-than conditions only. It gives no separate boundary row for exactly 5 kg or 12 mm.
- Select the material, final condition and required roughness on the component drawing.