On 20 Jan 2007 18:40:24 -0800, "DonMorrisey"
wrote:

I'm trying to figure out how and where to buy reamers. I need to
create some 5/8" and 1/2" holes in ultra high molecular weight
polyethylene blocks for my control system. The aileron push tubes
slide thorugh the blocks and the aileron actuators mount in the blocks
as well. The mounting component of my aileron actuator is 5/8", so
when buying the .6250" reamer is that already slightly oversized? I
have been told the holes should be oversized by .002". I have looked
for reamers on line but don't know if what I'm buying is the right
size, there is little or no description for them.

Can someone tell me what I should look for in buying these tools and
where may be the best place to do so?

Don, you've already had others say what I'll say, but hole sizes in
UHMW have not, in my experience, matched drill or reamer sizes very
closely as contrasted to metals. It has been my experience, as well,
that taking 0.005 out via reaming UHMW gives a different size hole
than taking 0.030 out. I'm with the camp who suggest adjustable
reamers if you feel the need to ream, otherwise, use a drill and be a
little oversize. Remember that the expansion of materials is
different, binding would not be a good thing.

I'd definitely pre-ream(drill) to a specific size before finish
reaming(drilling). I'd run the tool very slowly and "lube" with only
compressed air.