I need to ream holes that will range between 3/16" and 1/4". The
actual size can vary due to the fact that what goes in the hole can
vary widely, but needs a proper fit. Right now, I'm drilling and then
filing with a small round file, but an adjustable reamer would really
be better. Just can't find any less that 8/A (1/4" +). I'm working
with plastics, so the material is not hard. Anyone have any
suggestions?

Thanks,
Bruno

"Bruno" wrote in message
...
I need to ream holes that will range between 3/16" and 1/4". The
actual size can vary due to the fact that what goes in the hole can
vary widely, but needs a proper fit. Right now, I'm drilling and then
filing with a small round file, but an adjustable reamer would really
be better. Just can't find any less that 8/A (1/4" +). I'm working
with plastics, so the material is not hard. Anyone have any
suggestions?

Thanks,
Bruno

Chucking reamers are available in number, letter and fractional sizes,
probably all metric sizes as well, so if it's critical, assuming you're
willing to invest in a variety of sizes, you should be able to buy anything
you need. The one concern is if the plastic in question lends itself to
reaming. If it's too soft, it may not cooperate. Nylon, for example,
would be a bitch to work with.

I can't imagine you'd find adjustable reamers when you get down to that
size-----but I could be wrong.

Harold

According to Bruno :
I need to ream holes that will range between 3/16" and 1/4". The
actual size can vary due to the fact that what goes in the hole can
vary widely, but needs a proper fit. Right now, I'm drilling and then
filing with a small round file, but an adjustable reamer would really
be better. Just can't find any less that 8/A (1/4" +). I'm working
with plastics, so the material is not hard. Anyone have any
suggestions?

How thick is the workpiece? If it is thin, and you can live
with a little taper, get some taper pin reamers, and just run one in to
whatever depth gives you the desired size.

Soft plastics can be reamed just a little undersized, and
expanded with whatever you are fitting into it.

Brittle plastics will need to be reamed to full size, or perhaps
drilled oversized and bushed.

The fact that you are adjusting the size with a file suggests
that the actual precision needed is not that great -- unless you are
*good* and *patient* with those files.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Bruno wrote:
I need to ream holes that will range between 3/16" and 1/4". The
actual size can vary due to the fact that what goes in the hole can
vary widely, but needs a proper fit. Right now, I'm drilling and then
filing with a small round file, but an adjustable reamer would really
be better. Just can't find any less that 8/A (1/4" +). I'm working
with plastics, so the material is not hard. Anyone have any
suggestions?

If this is e.g. a plastic box, let me tell you a story. I grew up completely
ignorant, even helpless, around tools. I was very curious, however (still am)
and used to get into all sorts of jams. One time I was trying to make a little
electronics project and I made a horrible botch of drilling a hole and my
father-in-law, a former tool and die maker at Dodge, laughed and got out a
tapered repairman's reamer. This isn't really a precision tool, this was
probably the kind you'd see in a rack of tools made by General at a tool store.
A few quick twists and that hole was nice and round.

I bought one right away and have had it ever since. Works just great. Here's one
that costs a bit more than I remember but you can see what it looks like:

http://www1.mscdirect.com/CGI/NNSRIT...PMT4NO=3406111

GWE

Thanks Harold, Grant and DoN for your responses.

The application is fitting nibs into sections on fountain pens so the
size of the hole is dependant on the individual nib and feed used.
They can vary all over the map, but the hole should be to within about
a thousandth to get a tight seal. The materials are generally acrylics
or hard rubber. The depth of the hole can be about an inch, although
the critical part of the diameter is the area close to the top.

So, step sizes are not the best choice. A set of tapered reamers is
not a bad thought since the top part of the hole can be a touch
larger, and that's where the real seal needs to be.

I was just figuring an adjustable reamer would make the job easiest
without buying a ton of tools.

-Bruno

Bruno wrote:

I need to ream holes that will range between 3/16" and 1/4". The
actual size can vary due to the fact that what goes in the hole can
vary widely, but needs a proper fit. Right now, I'm drilling and then
filing with a small round file, but an adjustable reamer would really
be better. Just can't find any less that 8/A (1/4" +). I'm working
with plastics, so the material is not hard. Anyone have any
suggestions?

Thanks,
Bruno