Annealed 4140

[EdK]

(01-07-2013, 05:56 PM)PixMan Wrote: What kind of turning tools do you have, Ed? I have some GREAT steel turning inserts I could send you to try. If you have insert holders just let me know what they are and I'll happily send you some inserts.

Ken,

That is most generous of you. Thanks a million!

I have this insert turning tool kit I got from latheinserts.com.

http://www.latheinserts.com/1-2-HOBBY-LA...he-kit.htm

I also have a handful of Micro 100 cemented carbide turning tools and some HSS turning tools.

I need to invest in some more insert turning tools for sure.

Ed

[PixMan]

I do have some that will really work well in that material. PM me with your mailing address, they'll be in the mail tomorrow. I did give a good many of what I had to some Autralian fellow recently, but still got a few. ;)

[Mayhem]

(01-07-2013, 06:38 PM)PixMan Wrote: ...I did give a good many of what I had to some Autralian fellow recently, but still got a few. ;)

What? You hid some?? I do recall you gave some to Jennifer too, so I cannot be held fully responsible to slightly denting the inventory

Whilst I haven't tried all the different grades/top form geometry combinations, the one I have tried in 1040 steel did cut nice and produced a very nice finish (hand cranking).

Thanks again for the inserts Ken

[EdK]

Ken came through with not just one insert like I was expecting but eight inserts. Thanks a million Ken! You're a very generous man.

Ed

   

   

[PixMan]

My pleasure to be of help Ed!

Use the data sheets shown in the bottom photo to choose which inserts make the most sense for the corner radius, depth of cut, feed rate and speed you can run. Let us all know how you make out with the 4140 turning application.

[EdK]

Ken,

I need your help on deciphering the code. See attached image.

I'm assuming the f [ in / rev] is SFM. Is that correct?

I don't know what those small numbers are referring to .004|.016|.024. Are those depth of cut numbers?

The larger numbers in the blue section. Are those RPMs? I'm guessing not.

Thanks,
Ed

   

[TomG]

Ed,

I can answer that in case Ken's not around.

The F[in/rev] is the feed rate in inches per revolution, .004, .016 and .024 inches per revolution to be specific. Your lathe feed numbers are likely in inches per minute so you'll need to convert.

The larger numbers in the blue section are cutting speeds in surface feet per minute. RPM would be 4 x diameter of work / cutting speed.

In general, carbides like high feed rates to carry the heat away, so these feed rates will look fast compared to high speed steel.

Tom

[EdK]

(01-12-2013, 01:32 PM)TomG Wrote: Ed,

I can answer that in case Ken's not around.

The F[in/rev] is the feed rate in inches per revolution, .004, .016 and .024 inches per revolution to be specific. Your lathe feed numbers are likely in inches per minute so you'll need to convert.

The larger numbers in the blue section are cutting speeds in surface feet per minute. RPM would be 4 x diameter of work / cutting speed.

In general, carbides like high feed rates to carry the heat away, so these feed rates will look fast compared to high speed steel.

Tom

Thanks Tom. That clears up quite a bit.

Another question though. In the inches per revolution, I assume they are talking about the workpiece revolution? I know, that sounds like a dumb question but math has never been my strong suit.

Thanks again.

Ed

[TomG]

Yes Ed, the feed rates are in inches per revolution of the spindle or workpiece. I did some checking, and the feed rates on most lathes are in inches per revolution, so you should be able to use the feed rates in directly from the chart. My Hardinge has electric feed so it's been a while since I've used a lathe with feed rates on the quick change gearbox.

Tom

[PixMan]

Tom has it right, though I just noticed that the data sheet if for negative rake inserts and those I sent you are positive. Here's a photo of the correct page from the catalog. If you can't read it (I wouldn't be surprised), I can e-mail you a PDF.

The annealed 4140 would be the third group down from the top, the "high alloyed steels" and those shown as "annealed" in the first row. Follow that over to the grade you're using to get the cutting speed recommendation. Now discard that information because your lathe can't go that fast and you'd be afraid to stand in front of it if it could. ;)

Run the materials as fast as YOU feel comfortable, but do use the other pages I sent showing the various chipbreakers to pick the best one. Once you've selected a good chipbreaker with the feed range you need to run for the finish you want to get, then set your quick change gear box for that feed per rev. Now set a depth of cut that's also right for the chosen chipbreaker and have at it, with a VIDEO CAMERA in hand. :) I want to see this!