[BILLYD]

I am trying to machine an internal groove in steel. I can't seem to get from the customer what exactly the steel is, but it is not hard and is very gummy.
The problem is that I am going into a .260 hole with a solid carbide groove tool with a .250 minimum bore size. The groove is .460 deep and the tool is made for a .500 deep max. hole. It is 3/32 wide. I have tried numerous feeds and speeds but I keep breaking tools. The chips build up on the tool no matter what I try. Any suggestions would be appreciated.

[Jason S]

Break your depths into increments. Go .03 deep or so, retract out of part so the chips can be flushed out. Repeat until you get to the desired depth.

[extanker59]

It sounds like it could be CMI, a steel used for magnetic solenoids (redundant?).
IF it is, then high SFM and low feeds with very sharp tools AND follow Jason's recommendations.

[g-codeguy]

As you have already found out one of your biggest problems is going to be chips packing in the hole. I have a similar job (little bigger diameter, but no place for the chips to go cause I'm also using a bigger tool). I peck groove a ways, re-drill, peck groove, re-drill, peck groove, re-drill...well you get the idea.