.018 holes through 304 ss tubing

[buck30]

i need to drill 1200 holes through 304 ss tubing. Wall thickness is just .032

am using 15000 rpm and 2.375 feedrate but breaking drills after about 100 holes.

amyone got any suggestions of getting a few more holes per drill??

 

am using sphinx carbide Micro drills. maybe a better drill out there??

[Dave.L]

They will probably tell you not to peck, but I would peck at about .01.

 

We are using the same drills now (.024) on 50 Rc 17-7 PH....running production in the next day or two, it will be interesting to see how they work (only drilled one hole so far in setup).

 

In the past we have done small holes and the peck was critical.

[toddm]

i would always drill small (.030 and smaller) with a .001 (Q) peck, with a .005 (p) rapid return height (G83), with a feed of .5 F

a .024 drill i personally run it at 9200 Rpm. ( will take longer, but yo will not be busting any drills. ( or a hole popper would work too.)

[Dave.L]

I now have some better data for our application:

 

17-7 PH, Rc 42-49. 0.0244" Sphinx DR, .060 Deep (Thru hole). Ran 65 SFM and .0001 FPT and drills where cutting oversized after 12 holes, same result if we pecked verse no peck.

 

I cut the SFM to 30 and kept the feed the same (.0001 FPT) and I took the peck out. We are now above 60 holes with no issue (job running as I type this).

 

We did not break drills, we need to hold +/- .0004" tolerance and after 12 holes the tool was getting dull and cutting .025".

 

Based on what I learned (and we are using the same drills), I would slow down your RPM. HTH

[buck30]

wow thanks Dave for that spacific info.

in my case the hole dia is + - .003 so not as close as yours.

i have been running 15000 RPM and 2.375 Feed and getting 320 holes at a time.

will change to your nimbers and see if i get another row or two of holes on a drill.

 

Thanks again

[Dave.L]

wow thanks Dave for that spacific info.

in my case the hole dia is + - .003 so not as close as yours.

i have been running 15000 RPM and 2.375 Feed and getting 320 holes at a time.

will change to your nimbers and see if i get another row or two of holes on a drill.

 

Thanks again

 

 

Buck, your welcome. We got thru the rest of the lot with no issue (about 120 holes on one drill). Remember, your material is different than ours so I would not run our numbers, but I would slow down your speed.