I'm not a metal worker

[false_aesthetic]

So forgive the basicnessosity of this question:

Half-round files: How do I figure out the radius of the file?
In other words, do all/most 8" half-round files have a certain radius, all 10" have another... etc with 12" + 14"?

I was in the sculpture studio today and realized that no one had ever explained this to me -- I've always just chosen one that seems a little bit smaller than what I need and made it work.

From the looks of it, the 8" half-round I was using has a radius close to 1" but I'm just eyeballing it.

Google wasn't cooperating with my question.

[Jacques]

I can't tell you if given lengths of files come with standard radii, but if you've got a few on hand they should be easy to measure. Measure the width (the circle segment's chord) and height (total height - height of any square edges) and plug 'em into this formula:

r=(c^2+4h^2)/8h

[false_aesthetic]

r=(c^2+4h^2)/8h

i think i was absent from geometry that day.

thanks!

[Eric Estlund]

Short answer- yeah, they are standard (ish) across brands. "Ish" because not really, but close enough.

Long answer- with a little wrist action and some practice it doesn't matter much.

8"/1"
10"/1.125"
12"/1.25
14"/1.5"

[bellman]

i think i was absent from geometry that day.

thanks!

You and me both, but I think what he means is add the square of half the width to the square of the height and divide by twice the height

[Jacques]

You and me both, but I think what he means is add the square of half the width to the square of the height and divide by twice the height

That's the square of 1/4 the width!

[bellman]

That's the square of 1/4 the width!

There was a split second there that i wasn't confused. Its gone now.......:-)