PCB drill bits are made of carbide, whereas the bits from the hardware
store are just steel.
PCB material is generally resin/epoxy impregnated fiberglass, which is
very abrasive. Drill a few holes with a non-carbide bit and it'll be
dull before you get even a small board drilled.
I drilled some thin PCB with a regular drill bit, look at how nasty
the holes are even with a brand new non-carbide bit:
<
http://groups.yahoo.com/group/Homebrew_PCBs/files/Sign_Cutter_to_make_PCBs/GeigerPCBScan01.jpg>
Steve Greenfield
--- In
Homebrew_PCBs@yahoogroups.com, Kenneth Long <kelong_2000@y...>
wrote:
>
> n00b question... what's special about PCB drill bits,
> as opposed to what's available at Home Depot or Lowes?
>