countersinking soft aluminum

I have to countersink some pre-drilled holes in ~.1" thick VERY soft aluminum. The holes are for 100 degree #6 flat head screws. I would
appreciate any suggestions about the best type of tool to use, best rpm, etc. Last time I seemed to swage as much as I cut and I was using a new, supposedly sharp tool.
Thanks
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jack Adams wrote:

I'm sorry. It sucks to be you.

Go slow on the rpm. A fluteless countersink might be good, and a good lube really helps. How many holes? If it's only a few, you might be time and money ahead just using a sharp corner end mill running up and down the angled surface inside the hole.
Later,
Charlie
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
CLIP

CLIP
With super-soft alum. this seems to be a key "ingredient" as they say... The best, most ridgid machine with brand new, super high-trech tooling will have problems in soft aluminum if it's not lubed up...
Personally, there is a lube sold by TapMatic (I think) that they suggest for alum. tapping. I've found it to be the best lube I can find for some aluminim drilling processes so it may work wonders for you too...
--


Regards,
Joe Agro, Jr.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I have A-9. Someone recommended that. These parts are single sided aluminum core PCBs. I'm very concerned about contamination and delamination. The A-9 didn't seem to harm the boards before.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jack Adams wrote:

Jack, I like the single flute Ford brand single flute countersinks.
--
Regards,
Steve Saling
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

is this on machine or by hand
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.