Hey guys, excuse me I'm still new to this. I am roughing a 1" dia. 12L14 mild steel at 200 sfm and .01 ipm at .1" per pass. I seem to be burning up my insert very quickly. It is a carbide coated insert and I am using coolant. Any suggestions.

Way too slow! (especially feed, and probably SFM)

With insert tools, you kind of need to start with the manufacturer's recommendations. Sometimes the intended use will blow your mind. For instance, we dry mill mild steel (1020) at 1300 sfm with Sandvik inserts, and I know the high-feed insert tools take advantage of feedrates that are simply unbelievable. Haven't had the chance to use one of those yet.

Also, use air blast instead of coolant on insert tools in steel for milling, turning is different, since the cut isn't [normally] interrupted. The thermal shock will greatly reduce insert life.

If you don't have the manufacturer's data, somebody here can give you a starting point, but you'll need to provide a bit more detail on your tool and application.

Justin

Speed it up!! 12L14 is like cutting butter, it's extremely easy to machine. Ultimate feeds and speeds depend on equipment and tooling being used but what you lisited in your post is way too slow. I would start at 800-1000 sfm and feed a minimum of 35-40 ipm as long as the machine will handle it. Don't be bashful with this stuff, it cuts easy and is pretty forgiving

:cheers:

Ok, I will try that. My reasoning for using those numbers was that the insert is a
Kennametal KC730 carbide 80 degree pin and clamp insert. They recommend a feed rate of .012 to .028 ipr. Also the chart I have to determine sfm (which may be out dated) recommends 100 sfm for mild steel, doubled if using carbide.

I'm thinking my old school cnc lathe can handle that. I havent topped her out yet but I think she is capable of 5000 rpm. Its a Wasino LJ-103m.

Throw out your current S&F chart and get the S&F directly from Kennametal's website specific to the insert you are using.
Like you said .012 - .028 IPR you need to at least double your feedrate and then crank up th SFM.
Have Fun

Crashmaster, follow DareBee's advice. The S/F you mentioned yesterday were the correct numbers for BEFORE my apprenticeship 45 years ago. If that Wasino's in anywhere near decent shape, it should handle it. Start at minimum new K/M rec. and build it up from there.

.01 ipm ???? I'm hoping you meant .01 ipr. KC730 is PVD TiN coated so I'd start at about 400 SFM (1500 RPM) and 12 to 18 ipm feed. Then I'd try double those numbers.
Bob