Spd & feed in Al bronze

I know this subject has been discussed ad nauseum but I see conflicting info.

Question is I have a 0.625 dia. indexable drill that I will be using to drill through holes in a sandwich of 1" of Al Bronze then 1" of CI. Inserts are (home now and I do not recall the proper designation) however they are ~1/8 square with chip break edge, I can provide the actual number on Monday.

What feeds and speeds have ya'all had success with? To peck or not?

I have the option of thru spindle coolant (I think this might be best), flood or mist.

Running the operation on a VMC 30 HP & max spindle speed of 6K, Cat50 holders.

I have run this job before using HSS twist drills with dark cutting oil and I get about 48 holes before the Al B. wears the flues and drill starts getting stuck on the Al B. when it reaches the CI on the bottom, if this makes sense. HSS was not my choice that one came from the boss man.
As far as the twist drills I was running about 175 to 200 ripp'ems fed at ~ 3 ipm.

Please excuse my ignorance but I run CI 99% of the time.
Thank you for any info.
D

Bronze is 954.

Definitely thru-spindle, if for no other reason but to get the swarf out of the hole.

If you have good TSC pressure there should be no need for pecking.

Pretty sure you can do better than 200 RPM with an inserted drill :-). 1,000 RPM? That's 160 SFM. My inserted drills don't like a heavy feed, usually .003"-.005" chipload. Since inserted drill is a 1-flute tool, you do lose half of your IPM unfortunately.

Regards.

Mike

doug8cat said:

Bronze is 954.

Click to expand...

Be glad yah got one of the "easy" ones, then...

Thanks guys the job went great ran at 200 SFM. got 48 holes per edge on the inserts. Could have gotten more but didn't want to press my luck.