How do you identify grind types?

[Starfish]

I'm beginning to think that you guys have a secret decoder ring that you place over the posted images in these forums that tells you whether a knife has a flat grind, hollow grind, saber grind, etc. etc.

I've read the FAQ, looked at knives that I own and know what grind type it is (from reading it here), and I still can't see how to tell the difference! Especially when just looking at a picture like some of you do!!!

So what's the secret?

 

[Gollnick]

There's a brief, incomplete article on my site

http://www.balisongcollector.com/grinds.html

That's a start.

 

[Cliff Stamp]

Sabre grind just means partial height, so that is easy to tell. Flat or hollow or convex can be read from the way that the light reflects, sometimes it is obvious, some times it is not. As well, most makers are known for one type of grind so if you know who made the knife, you generally known what way it was ground.

-Cliff

 

[Esav Benyamin]

Well, Starfish, I can't speak for the others, but I do use my secret decoder ring ...

Seriously, what you have to look for is the direction of the curve that light striking the blade will make. If the reflection is bowed in, it's hollow ground, if it's bowed out, puffy, it's a convex grind. If the reflection shows no curve, it's flat ground.

It's also important to note where the grind starts. A flat grind is defined as starting at the very back of the blade, or very close to it. If it starts way down the blade, it's called a saber grind.

In all these cases we are describing the primary grind, but you could use the same terms on the secondary bevel, at the very edge of the blade, where the real cutting gets down. This is usually a flat grind, especially if one of us has been resharpening it. But a careful job with a belt can get a stronger grind yet on that secondary bevel, a convex grind, or rolled edge.

Now re-read some of the posts you were referring to, and think about this: some of the guys may not have been telling you what they saw in the pictures -- which may not have been clear enough to identify the grind -- but letting you in on what they already knew about that particular model.

 

[PhilL]

Originally posted by Starfish

I've read the FAQ, looked at knives that I own and know what grind type it is (from reading it here), and I still can't see how to tell the difference! Especially when just looking at a picture like some of you do!!!

So what's the secret?

Try this with your own knives. Take a business card and lay the edge of the card on the grind of the blade, look real close and with a hollow grind you'll see it doesn't touch the card in the middle, on a flat grind it will, and on a convex you'll be able to rock the card from top to bottom. But once again just seeing how the light hits the grind is enough for most people to tell even in a photo.