| ISO | Material | Material Designation | Material Condition | Hardness | Cutting Speed Recommendations (Vc) |
| N | 21 | Aluminum-wrought alloys | Not hardenable | 60 HB | 1150-3360 sfm |
| N | 22 | Aluminum-wrought alloys | Hardenable | 100 HB | 865-2470 sfm |
| N | 23 | Aluminum-cast alloys <=12% Si | Not hardenable | 75 HB | 905-2895 sfm |
| N | 24 | Aluminum-cast alloys <=12% Si | Hardenable | 90 HB | 615-1765 sfm |
| N | 25 | Aluminum-cast alloys >12% Si | High temperature | 130 HB | 570-1040 sfm |
| N | 26 | Copper alloys >1% Pb | Free cutting | 110 HB | 575-1105 sfm |
| N | 27 | Copper alloys | Brass | 90 HB | 440-840 sfm |
| N | 28 | Copper alloys | Electrolytic copper | 100 HB | 300-575 sfm |
| N | 29 | Non metallic. | Duro& fiber plastics | | 165-655 sfm |