Fortunat1 wrote:
Another stupid question!

Been reaming holes in a few 4130 plates. The reamer worked fine for about
20 holes and then the holes started getting a bit smaller to the point the
bolts got a bit snug.
In my ignorance I thought this one hand reamer would pretty much last me
the whole project, but it's obvious I'm going to need a half a dozen of
them at least just to do the wing hardware.
I did a bit of searching on the net and found some info on reamers. All
hand reamers seem to be HSS which would put me back in the same boat I'm
already in so I was tempted by the carbide reamers I saw for sale.
So, my question is; can you use a carbide tipped reamer designed for use in
a lath in a simple drill press effectively? Or, for that matter, can you
use a reamer designed for use in a lathe as a hand reamer?
Or am I just barking up the wrong tree altogether?

By the way, just for info, the holes I've beenreaming are 5/16 and 1/4. The
material is .090 4130 and the holes were all laser cut about 1/64
undersize. I would ream the first hole in each plate and then clamp
together the plates in pairs to ensure accurate alignment of the holes in
each pair of plates.
Just in case it's not the reamer's fault at all!


As has already been mentioned laser cutting has hardened the metal
around the hole. if your drill press runs true go with the carbide
tipped. Avoid solid carbide since the average drill press doesn't run
true enough to prevent breakage. If you need a very smooth bore go with
a spiral reamer, if not go with straight. Depending on size and from
whom you purchase the difference in price can run from about a dollar to
slightly phenomenal. As has also been stated use cutting oil and debur
the reamer as needed.

Things that can reduce reamer life: rotating them backwards, wobbling
when used, spun too fast, not using cutting oil, poor storage practice,
using the wrong type for the material, not cleaning the reamer after
use, drilling too small a hole before reaming and throwing across the
room when you discover you were supposed to use an under size reamer
vice the over size one you just used (the most entertaining time for
this to happen is after you have spent hours getting to the point you
need to ream and you are almost finished). In short use common sense.

Having said all this I will add having an extra reamer in sizes you
will use a lot is handy.

I have also noticed plans for various projects I have worked on have
one thing in common: the more complicated the project the more likely
they will call for a size I don't have. This is why I have about 80
different sizes ranging from 0.0135 ( I don't even remember what I used
it on) to 1.5" which I have used for steam engine cylinders.

Good luck with your project.

Dan, U.S. Air Force, retired