On Nov 3, 11:58*pm, jay wrote:
Hi there
I use files quite a bit in my shop.
I grab one & feel it's coarseness w/ my thumb & look @
it's shape to decide whether to use it or another. I've never
known what I was actually using. I've decided
to buy a few USA made different lengths & cuts all @ once.
After looking @ some catalogs, I've come up against the same
question I've been wondering about for years:
How do I find out what the coarseness of 1 length file of
a given cut is compared to a different length of a different cut.
For example: Is a 6” ******* courser than a 14” 2nd cut?
Or, is a 14” smooth cut smoother that a 6” 2nd cut? If so how can
I find out what it is & by how much.
I've read Machinery's 28th pages 962 through 965. Nothing.
Nothing that gives me definitive quantitative answer.
I've Googled, I've looked in Wikipedia.
The only thing I found is a photo of 3 files that says something to
the effect of “a ******* has ~ 25 teeth /in; 2nd cut has ~35th /in;
& a smooth cut has ~ 60th/ in”. (These # aren't accurate, I'm not
looking @ the site, they are from memory, but in the ball park)

Also I don't remember having ever used a file that the handle would
stay on. I probably have but just don't remember it. The files I buy
will probably not have handles. Who makes an after market handle
that stays on. Maybe I should buy the cheapest wooden ones &
epoxy them in place. I assume that would work. No?

Thanks for any info, JD

You'll find different manufacturers have their own ideas as to what
constitutes a "smooth" cut file, for example. And needle files used
to have numbers corresponding to how fine the cut was, no
corresponding between makers. Same cut in the same manufacturer's
line should be the same TPI no matter what size or pattern the file
is. Somewhere I've got a really old shop manual naming the cuts
available back then with TPI ranges and photos of the various
patterns. You'd be lucky today to find a 10th of the different ones
thay had back then.

file handles:
Best I've found has been one sort that has two ridged jaws like a
brace chuck. Opens up in a taper, you turn a knurled disk on the end
and it draws the jaws back inside. Doesn't lose its grip, either.
Ace has had them, ditto True Value. You can make your own with a
little work, wood is easy to free-turn on a lathe, then use copper
plumbing pipe for ferrules. Have several of that sort, too, they
don't come off. You're supposed to PUSH with the things, not beat the
work on the head or drag the file with as much down pressure backwards
as what you do forwards.

Stan