I need to do a lot of deep holes in UHMW material. Generally, these
holes are 5/16" dia (loose tolerance) by 6" deep...sometimes deeper.

Using standard style long drill bits works ok..but there is a lot of
pecking and the stringy chips tend to bind etc. I was wondering if
anyone out there had any ideas for speeding up this process? Also, UHMW
tends to dull bits fairly quickly. It's not terrible and 5/16" drills
are easy to re-sharpen..but it would be nice to reduce this a bit.
Carbide tips hold up ok, but it's hard to get the nice sharpness that
UHMW likes to see when using carbide material.


Thanks for any ideas


Koz

try a parapolic drill

TLKALLAM8 wrote:

try a parapolic drill

Agreed. Also, UHMW is self lubricating, which is good, however, you are
likely generating a fair amount of heat. Likely that is a big factor in
the short life of your cutting tool. If you can flood with coolant, use
a spray mist, or an air blast will help alot. TiNi coated drills will be
effective, as that is a coating with excellent resistance to heat.

michael

Drill slower and more pressure to bring the chipload up. High speed is
killing off the sharpness and the thin swarf is making the drill cut more
material.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works evevery time it is tried!