| ISO | Materials | Material Designation | Material Condition | Cutting Speed Recommendations (Vc) |
| N | 21 | Aluminum-wrought alloy. | Not cureable : 60 | 300-1500 m/min |
| N | 22 | Aluminum-wrought alloy. | Cured :100 | 300-1500 m/min |
| N | 23 | Aluminum-cast, alloyed <12% Si. | Not cureable : 75 | 300-1500 m/min |
| N | 24 | Aluminum-cast, alloyed. | Cured : 90 | 300-1500 m/min |
| N | 25 | Aluminum-cast, alloyed >12% Si. | High temperature :130 | 150-500 m/min |
| N | 26 | Copper alloys >1% pb. | Free cutting :110 | 200-800 m/min |
| N | 27 | Copper alloys. | Brass : 90 | 200-800 m/min |
| N | 28 | Copper alloys. | Electrolitic copper :100 | 200-800 m/min |