jewelers loupe

Oct 4, 1998
I've decided to get a jewelers loupe to inspect my blade edges. What power is good? And, what the heck am I looking for when I check a blade?

It's easier to get forgiveness than permission

[This message has been edited by gester (edited 05 May 1999).]
I'm mostly using a 5x (have a 2 and 10x too). No quick answer to the second question, at least not from me (and it depends on what you are checking that blade for), but maybe something like "theory as manifested in reality/matter" might capture something? The 'theory', of course, refers to knowledge about sharpening, etc.

An issue of Knives Iluustrated from last year featured a story where the author inspected blade edges under a microscope and tried to predict which would be the best cutters based on what he saw. The article wasn't written all that well, and as far as I could tell, his predictions were wrong, but he also didn't make any final conclusions. You may want to chase the article down, though, and give it a read. I believe it appeared in the issue that featured a Katz Skinner on the front?
You also have to consider the diameter of the lens. A B&L 10x triplet is nice, but the lens diameter is only 16mm, rather small.
Gester - I've been using loups to study edges for 20 years. I carry a variety in my briefcase at all times. I recommend a 12X swing base loup made by edmund Scientific.
A microscope with some kinda light is best, as for a single loupe I like a 7x. 10x and 15x sounds nice if the Diameter is not too small like Shodar mentions. Can't beat a microscope though, many models out there.
Our shop gets used B&Ls from the assembly lines, have one at every lathe and mill, I think knife companies would do well to have them on the floor and not just maybe QA.

Ok, sorry guys if you use them already.

Mark Camp

[This message has been edited by mcfg (edited 06 May 1999).]

[This message has been edited by mcfg (edited 06 May 1999).]
I have a very nice Nikon jeweler's loupe that I use sometimes, it does all the fancy things like minimize chromatic aberration and distortion, etc. However, this loupe was bought for what it was intended for, specifically for examining gems, not knife edges. For examining edges, you don't need fancy optics that minimize chromatic aberration. And I've also come to the conclusion that I'd like something stronger than the standard 10x loupe power. I've been thinking I'd check out one of the 20x tube microscopes sold here and there for $50-$100.

What I tend to look at is anything to give me hints for my sharpening technique. Is there any tiny burr left? Perhaps I didn't get all the burr off in one place or another, and I can be sure to give that area more attention from now on. Does any part of the edge look less finished than the rest? Maybe I missed that area on my finest stone. Are any of the bevels sloppy? Maybe my accuracy had problems today.

Quick question- just *where* does one find a loupe for purchase? Inquiring minds want to know...

"If historic fact exists, it is this- that all of the history of man's civilization, from the caves to civilized or so-called civilized man, is a progressive limitation of liberty."
-Benito Mussolini

[This message has been edited by Christian (edited 07 May 1999).]
If you really want a jeweler's loupe, with the distortion-free and chromatic-aberration-free optics, you can try Gemstone Press at 1-800-962-4544. They have the expensive but excellent Bausch & Lomb loupe for $45-ish, and a less expensive Vigor loop for $25.

If you don't need all that stuff, just go to Edmund's web site, they sell all kinds of different loupes and magnifiers.

Edmond Scientific sells a nice little 10x magnifier, not a loupe, for about $10. That's what I use.

What am I looking for? Obviously, any small chips on the edge. Signs of wear. Signs that it's been sharpened in the field. Any little, tiny rust freckles forming. Look at the markings. Check out any file work. And also inspect any other character lines and features on the blade or other parts for workmanship. On the handles of fixed knives, check for tiny cracks forming around any screws or rivits. Those may grow over time, especially with use, especially if the knife is dropped, and they may also grow if the knife is subject to temperature and/or humidity changes. Other materials prone to cracking, such as Mother of Pearl, should be closely inspected for signs of cracks already starting.

What have I left out?