Need Help!- Threading D2

[Billet Sean]

I've got a job to do tomorrow that I have to single point thread D2 in our cnc lathe. It's 1 1/4" O.D. and the pitch is 12. We thread 1045 all the time. We go at 750rpm and take .005" a pass. Here's my question: Can I cut the D2 at a similar speed and DOC?

[g-codeguy]

Kennametal catalog puts D2 in the same group as 1045. You shouldn't have a problem. I would consider D2 to be a little tougher than 1045, but you are already running a little slower than I would be in that grade, so I'd say "Go for it." Course you don't mention the grade of insert, so your rpm could very possible be less than what it would be for the grade I use.

[Billet Sean]

I use Iscar 16ERM AG 60 IC250.

[juergenwt]

Go slower - feed less.

[g-codeguy]

Familiar with Iscar cut-off inserts only. According to their catalog you should be starting at 427 sfm. Provided I am looking at the right material classification. Your first pass is at about 241 sfm and will only go lower as you thread. I see no need to go slower. Or take less DOC. I assume that is what juergenwt is referring to. D2 isn't hard, tho maybe a bit gummier than something like 4340. I assume it hasn't been heat-treated.

Would like to know how you make out with it. Thanks.

[Billet Sean]

The D2 material turned a lot better then I had thought it would. It's very gummy though. He had me go ahead and finish up the part and drill a 1/2" hole and a large 20deg. C.Sink while I had it setup. I burnt up one drill, but that's because I had the RPM's to high. Anyway, wasn't that bad. Oh yeah, don't use coolant on carbide inserts with this stuff. It'll doink them fast!

[g-codeguy]

Originally Posted by Billet Sean The D2 material turned a lot better then I had thought it would. It's very gummy though. He had me go ahead and finish up the part and drill a 1/2" hole and a large 20deg. C.Sink while I had it setup. I burnt up one drill, but that's because I had the RPM's to high. Anyway, wasn't that bad. Oh yeah, don't use coolant on carbide inserts with this stuff. It'll doink them fast!

Thanks for the follow up. Appreciated.