Turning OD grooves in HHS drill blank rod

Hi all ..... I'm having issues with turning .040 wide grooves in HSS drill blank rod.
Material is .377 dia. I seem to be eating carbide inserts doing this. I'm doing this manually.
What would be the recommended RPM, and grade of carbide to use? I only have 8 pieces to do, and don't want to eat up an entire shift to complete.
Any input on this would be greatly appreciated

Is the drill rod full hard? What alloy? What inserts are you using now, and current speeds/feeds? What is the insert failure mode?

How are you holding the material? Are you getting excess vibration? Are you using coolant or oil? How deep do you have to cut? What machine are you using?

More info is always better...

How long is the rod? How much do you have sticking out of the collet/chuck? Is it supported at the tailstock end?

Use a collet .Highest speed your lathe will go (probably still to slow).Use a hardened bushing in you tailstock .Sandwich your toolbit as close as possible.It would be nice if you could set an x stop,so that you could plunge in and get out quickly without dwelling. I have also used a thin 1 1/4 OD cut off wheel held in an air pencil grinder that was clamped in my aloris toolholder.If this is just for a retainng ring ,it will work .I have done this.HOWEVER,if you must meet some drawing tolerance ,that is a diferent story. Good luck Edwin Dirnbeck

I've had good luck with the "Nikcole mini-systems" for grooving and threading:

NIKCOLE - MINI-SYSTEM Holders for GIE Style Inserts | 697225 | Travers Tool Co., Inc.

Slow speed/feed and plenty of cutting fluid.

Hi All:
I'm with Edwin Dirnbeck on the notion of cylindrical grinding them in.
In my opinion, this is a hopeless task, trying to turn them.
I don't think you can exert enough pressure to get an 0.040" wide cutoff blade to plunge into HSS without eventually pulverizing the tip of the tool from the pressure.

There comes a point when it's just way too hopeful and ambitious to try to do a job for which you don't have the proper gear.
Now I'm all for stretching the envelope when it makes sense to do so, but I doubt that this is one of those cases.

However if you DO insist on trying to beat this into submission, you will likely have best success with a narrower blade dropped in maybe 0.005" at a time . then pulled back out, then shifted to the other side of the slot, then dropped in 0.005" deeper, then pulled back out and shifted back etc etc until you get to the bottom of the slot.
Make the tip of the tool only just barely longer than the depth of the groove so you can exert some force on it without buckling it, make sure your tool tip is tiny bit below center, do it slowly and without cutting oil, but maybe with a smidge of Moly Dee or Rapidtap and pray a lot as you try.

But this is literally a 20 minute job with a toolpost grinder or a cylindrical grinder...I'd spend more time fucking around trying to make the cutter than I would grinding the job complete.
So I encourage the OP to either rig a toolpost grinder (even if it's jerried together from a die grinder, a 2 x 4, and a couple of hose clamps) or farm the job out to someone who can do it without having to tear their hair out.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

I have some Nicole tools and also some $10.00 pos cut off grooving tools that I groove and cut off drill rod and hardened dowell pins frequently. Drill rod annealed will work harden very quick especially if the tool is not on center.Also forget about high speeds because of the work hardening 400 - 600 rpm is slow for that dia in most steels but something that work hardens just timidly touching the work at high speeds will harden it instantly. As I said I do this regularly.Goes very quick hand feeding no other process I have found is as quick or accruate.
I have grooved hardened rods but go real slow , shallow grooves for snap rings is quick any way.