Machinability Ratings

Every Material has a Machinability Rating that tells us how Machinable that Material is.  Below is a quick chart that shows the Machinability Rating or Estimate of Machinability for the most common materials we see. 

Here is how you use this: 1212 Steel is at 100% machinability and that gives us a baseline to go off of (500 SFM is a good starting point for 1212 Steel). Compare that to 12L14 Steel, which is at 170% Machinability, this means that 12L14 is easier to machine than 1212 and this allows you to run at high SFM (500*1.7=850 SFM) and means you will see greater tool life.  If you compare the opposite, 316 Stainless Steel is a 40% Machinability, this means that 316 Stainless is 60% less machinable than 1212 Steel and you need to run it at lower SFM (500*.4=200 SFM) and your tool life will be lower.  

Carbon Steels:

1018: 78%
1040: 64%
1144: 76%
1212: 100%
12L14: 170%
1215: 138%

Alloy Steels:

4130: 72%
4140: 66%
4340: 57%
8620: 66%

Tool Steels:

A2: 42%
D2: 27%
M2: 39%
O1: 42%

Stainless Steels:

303: 78%
304: 45%
316 (316L): 40%
321: 36%
410: 54%
416: 110%
420: 45%
440: 45%
15-5PH: 32%
17-4PH: 30%
A286: 18%

Cobalt Alloys:

Haynes 25: 16%
Haynes 118: 12%
Stellite: 16%

Nickel Alloys:

Hastelloy C: 25%
Hastelloy G, N, W & X: 18%
Hastelloy S: 25%
Inconel 625: 16%
Inconel 718: 16%
Nickel 201: 60%
Nimonic 101, 90, 91: 10%
Nimonic 105, 80A, 901: 18%
Rene 95: 6%
Udimet: 12%
Waspalloy: 14%

Titanium Alloys:

Titanium (Pure): 45%
Titanium 6AL4V: 35% 

Non-Ferrous:

These are just estimates and a baseline to start with.  If you have any questions or have a material you need advice on that is not on the list then Contact Us and we will get you an answer right away!  Hopefully this helps!