On 18 Aug 2015 08:58:25 -0700, you wrote:
>As a hobby builder I drill FR-4 with steel bits. They dull more quickly, but they are cheaper and will not shatter when used in sloppy tolerance hobby tools. Carbide bits require collet chucks in very precise spindle bearings.
I invested in more precise drilling equipment, using a Proxxon
mototool with steel collets running on a computer controlled linear
bearing. (overkill perhaps, but it works well).
>
>I use 1/32, (.032) diameter bits for most through hole construction. These cost about 50 cents each when purchased in 12 or 24 packs from buydrillbits.com. ( I have no financial interest in that company.) The 3/64 bits are used for larger component leads.
I've done #73 carbide drill bits without problems. You do need to
remember not to move the board itself.
The local prices of carbide bits are approximately 1.00 USD each, but
they will last a long time.
>
> Numbered bits are more expensive
Certain that they are.
I do hand wired vias and mostly surface mount, so my requirements are
probably different than yours.
Harvey