[starCNC]

Hello everyone,

I have never work on metals before. How can i drill hole for cap screw?

[wms]

Starcnc,

Welcome to the world of metals.

If this is a standard flat head socket cap screw, (IE: with a socket head driver , an small internal hex drive hole) then it will be 82 degrees.
These are also called "flat head die bolts".

So you would use an 82 degree countersink after you drill the thru hole to countersink the hole to 82 degrees and the proper depth to allow the head to sit flush or slightly below the surface.

If it is a regular head or a Phillips head screw..most of these are 100 degree..so a 100 degree countersink would be most appropriate.

Countersinks are available from most all tool suppliers or industrial supply houses. And even better hardware stores.

[High Seas]

Your question piqued my interest too, (especially the flat head socket screw). FYI I found they're available at: www.mcmaster.com check out pages 2318 and following. Not cheap - but make for a very tidy finish. On plastics I've been using forsner bits - might try with ali. Cheers - Jim

[cnc2k]

is this the right kind of countersink?

http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

[ESjaavik]

You can use them. But then use soluble cutting oil or paraffin because they have too small chip space for aluminum. There are some with only 3 cutting edges and deeper spaces between them. I found these are much better for aluminum, especially if it's not handy to use any cutting fluid.

[cnc2k]

Are there any better kind of countersink? If so please send me a link where i can get it.

thank you

[wms]

Single flute counter sinks work good on both Aluminum and plastics.


Just one of many sources.

http://www.use-enco.com/CGI/INSRIT?P...&PARTPG=INLMPI

[DareBee]

As well as doing what you guys have already discussed I also like (especially for the larger C/Sinks) to use a multi-flute and profile it for a super nice and accurate finish.