I've milled pcb's with the mills - and drills. The motor
with chuck ran 12k RPM's - and side loads are death to the drill/mill.

They are carbide - and likely sharp. Often pcb drillers/plating shops
send them to be sharpened, but fail to come for them as the price for
new is close to grind cost.

So if you need tiny holes and are willing to live with short lifetimes -
do it.

I also used them in various materials - being carbide they are capable.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
"Our Republic and the Press will Rise or Fall Together": Joseph Pulitzer
TSRA: Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Originator & Charter Founder
IHMSA and NRA Metallic Silhouette maker & member. http://lufkinced.com/

On 9/25/2010 2:19 PM, Ignoramus10035 wrote:
eBay is full of those:

http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide

or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. Is using them totally out
of question, or just frustrating, or perhaps they are handly for small
work?

i