Thread: Saw File Hardness Measurements

Now for some work on the 4" Iridium DEST saw file. Amongst the files sent to me last year for testing was a Liogier 4" DEST file. It's a little widerer across the face (0.182") than is the Iridium 4" DEST (0.1795"). The apices of the two files are identical at 0.004".

To test the two files I used them to sharpen my 12ppi 26" Disston D-8. Each file was used to sharpen all teeth (crosscut) on one side of the saw. The rake on this saw is 10^o and the fleam is 25^o.

After filing each file was examined using a Fowler optical comparator with 10X magnification.

First the Liogier file. Edge upward.

Liogier 4 inch after sharpening one 26 inch 12 ppi D 8 edge.jpg

And the face.

Liogier 4 inch after sharpening one 26 inch 12 ppi D 8 face 2.jpg

Now the Iridium. Edge upward.

Iridium 4.0 after sharpening one 26 inch 12 ppi D-8 edge 2.jpg

And the face.

Iridium 4.0 after sharpening one 26 inch 12 ppi D-8 face.jpg

And a side-by-side.

Liogier above Iridium below after filing 12ppi 26 inch Disston D8.jpg

The Liogier is pictured above the Iridium file. The edges of the files used for this exercise face the bottom of the frame.

My impression of the two files is very favorable. Both maintained their bite throughout the sharpening with the Liogier giving just the faintest impression of dulling wile filing the last few inches of the saw.

Magnified examination showed that the Liogier file was rougher and somewhat more damaged than was the Iridium file. The Liogier file also has more visible imperfections than does the nearly perfect Corradi Iridium. They're very hard to tell apart by feel but the Corradi is going to last longer.

Interesting Rob. The Liogier is actually an EST, they have never made DEST (unfortunately). That particular file has also been used by the three different testers (one edge each), but no doubt has some life left in it.

Rob, I would also be interested in one or two or three Corradi files.
Let me know if a group buy goes ahead please.

Originally Posted by FenceFurniture

Interesting Rob. The Liogier is actually an EST, they have never made DEST (unfortunately). That particular file has also been used by the three different testers (one edge each), but no doubt has some life left in it.

Are you sure? I thought that among the files you sent there were four un-used, wrapped with paper, and the balance were used. This is one of the four that were wrapped.

Originally Posted by rob streeper

Are you sure? I thought that among the files you sent there were four un-used, wrapped with paper, and the balance were used. This is one of the four that were wrapped.

Ah! I remember now - I thought you were talking about the test files, but you're right, it was a newie.

Originally Posted by jhovel

Rob, I would also be interested in one or two or three Corradi files.
Let me know if a group buy goes ahead please.

No problem Joe. I'm going to buy several boxes to spread out the shipping cost.

Originally Posted by FenceFurniture

Ah! I remember now - I thought you were talking about the test files, but you're right, it was a newie.

Don't get me wrong, the Liogier is a very nice file, I'd give it a 4.5/5. The Corradi is just a little bit nicer at 5/5. I'm going to continue this work today and sharpen the 1870's era No. 9 gauge saw with these two files.

I'm loading a box (70lbs/$1000 limit) going to Australia over the next two weeks or so. If anybody wants me to trans-ship some Corradi files send me a PM

70lbs, thats a load.

An update. This edge of this Corinox needle file has now sharpened five saws. The first was a 12ppi 22" D-8. The second was a 9" 0.015" thick 16ppi dovetail saw, a 0.020" X 9" 14 ppi dovetail saw, then yesterday a 12" 14ppi Disston No.4 and a 16" 12ppi Disston No. 9. As you can see, no visible wear. This is at 1X magnification. The used edge is uppermost.

Corradi Corinox #2 cut USED needle file 5 sharpenings 1X view 042516a.jpg

Here the used edge faces to the left.

Corradi Corinox #2 cut USED needle file 5 sharpenings 1X view 042516b.jpg

The used edge uppermost at 10X magnification.

Corradi Corinox #2 cut USED needle file 5 sharpenings 10X view 042516c.jpg

So I have to wonder why they are not treating their normal saw files with Corinox....

Have you used any of their EST files yet Rob?

I've only done a little with the standard files. I'm planning more soon. I managed to break the tip off of this file in use and the color goes all of the way through. I'm fascinated by these files, they are too good to be true almost.
I've seen one statement that the Corinox is a surface treatment, I haven't found anything else about it. It is very hard.