Do you have a question? Post it now! No Registration Necessary
October 24, 2006, 6:46 am

Most if not all fabs I've tried now use drills sized in 0.1mm increments. But
it isn't clear to me whether they have any standardised way of applying those
stepped sizes to customer's jobs, especially on PTH.
What I'd *expect* is they would use the nearest drill size that provides a
finished hole matching or larger than the specified hole (obviously not larger
by more than one drill size step).
Some appear to work on providing a finished hole of the *nearest* size to that
specified, i.e. +/- 2 thou if using 0.1mm drill size steps.
Is there a "standardised" practice? What do you guys find?
(just p####d off after having to carefully ream half the plating out of 450
holes that were IMHO fabbed undersize).

Re: PCB hole sizing ....

The places I've delt with have always said they go oversize on the
finished plated hole.
But I moved to all metric hole sizes many years ago, so it hasn't been
a problem for a long time.

You had <<0.1mm tolerance between pin and hole size? - ouch. No chance
of using a bigger hammer? :->
That's why fabs usually oversize, far fewer complaints that way!
Dave :)
Site Timeline
- » How legal are Electronics Techs?
- — Next thread in » Electronics Down Under
-
- » Glowing Magnetron.
- — Previous thread in » Electronics Down Under
-
- » Aussies Love EVs ?
- — Newest thread in » Electronics Down Under
-
- » Replacing NiCd batteries in an obsolete Uniden UH-052XR radio?
- — Last Updated thread in » Electronics Down Under
-
- » Wyłącznik różnicowoprądowy
- — The site's Newest Thread. Posted in » Electronics (Polish)
-
- » A solid state replacement for the lowly 2D21 Thyratron tube...(sorry for the On-To...
- — The site's Last Updated Thread. Posted in » Electronics Repair
-