| MACHINABILITY RATINGS | 
								
									| MATERIAL | SPEED SURFACE FT/MIM | SPEED % OF B1112 | 
								
									| AISI B1112 | 165 | 100 | 
								
									| Nitronic 30 Annealed | 30 | 18 | 
								
									| Nitronic 40 Annealed | 40 | 24 | 
								
									| Nitronic 50 Annealed | 35 | 21 | 
								
									| Nitronic 50 Grade A or Level 1 | 34 | 21 | 
								
									| Nitronic 50 Grade B or Level 2 | 32 | 19 | 
								
									| Nitronic 50 Grade C or Level 3 | 30 | 18 | 
								
									| Nitronic 50 Grade D or Level 4 | 28 | 17 | 
								
									| Nitronic 50 Grade E or Level 5 | 25 | 15 | 
								
									| Nitronic 60 Annealed | 40 | 24 | 
								
									| Nitronic 60 Grade A or Level 1 | 38 | 23 | 
								
									| Nitronic 60 Grade B or Level 2 | 36 | 22 | 
								
									| Nitronic 60 Grade C or Level 3 | 32 | 19 | 
								
									| Nitronic 60 Grade D or Level 4 | 28 | 17 | 
								
									| Nitronic 60 Grade E or Level 5 | 25 | 15 | 
								
									| 17-4 PH soln treated | 75 | 45 | 
								
									| 17-4 PH aged | 60 | 36 | 
								
									| These machinability ratios must be recognized as approximate values.
										They are a reasonable guide to relative tool life and lower required for cutting .
										It is obvious, however, that variables of speed , cutting oil , feed and depth of cut
										will significantly affect these ratios. |