Chisel Grind...Why?

Holly! Molly! This thread took on a life of it's own. Thanks Folks I was just reading an april- 2002 issue of Blade Magazine with a title saying, Japanese or American which Tanto for you, and written by Joe Kertzman. In this article there are several different knifemakers commenting in it including Bob Lum talking about japanese blades. This article got me to thinking about them. I was basically wondering why more American knife makers chose to make a chisel ground kwaiken or tanto versus a double ground type knives which I believe are sexier also.
 
This thread really went off on a tangent...

94941-monkey-sigh-rimshot-gif-drums-K5UJ.gif
 
Not a big fan of the chisel grind. But the guillotine is a chisel grind. Hard to argue with it's results. Can't be all bad. Just saying.
 
Apology accepted :p
Very good point and thanks for the diagram. Am I right in thinking the addition of a secondary bevel on the convex changes this? I realise it changes the conversation from being about the edge to being about the grind more generally. I've done a crappy diagram for my own reference but I clearly haven't had enough coffee today :)

Once more just to beat a dead horse. You are correct, for fixed stock thickness and blade height, a convex DOES have a thicker cross section.

And that is becuase it has a more obtuse edge angle than the vee. (buggered)

But for a fixed edge angle....flat has a thicker cross section. (And in fact...get ready...for a given edge angle....hollow has the largest cross section.)
 
Once more just to beat a dead horse. You are correct, for fixed stock thickness and blade height, a convex DOES have a thicker cross section.

And that is becuase it has a more obtuse edge angle than the vee. (buggered)

But for a fixed edge angle....flat has a thicker cross section. (And in fact...get ready...for a given edge angle....hollow has the largest cross section.)

Yup. It all depends on how you look at it and what variables you hold fixed.

Here's another good video exploring aspects of convex geometries.

watch


Back to chisel grinds, I find the most significant challenge in using them for a wider range of general tasks is in orienting the blade in such a way that it's being used to its best advantage. It requires a greater degree of strategic thought in using them, as a rule of thumb. When people refer to handedness, it's a bit of a misnomer--it's just indicating the side on which deflection forces are biased, and the orientation of the blade relative to the work piece can have a big impact on the behavior of the blade during the cut.
 
I fell in love with the chisel ground tanto when I first held a BM970. I love how they look... like the facets on a stealth bomber.

 
When I cut a root veggie or a large squash, I often find myself canting the blade on flat ground knives so that the primary bevel is perpendicular to the cutting board. Works better and my hand did it subconsciously. I can see why chefs knives are ground that way. I think they excel at a few things but for general cutting, I wouldn't choose a chisel grind.
 
I fell in love with the chisel ground tanto when I first held a BM970. I love how they look... like the facets on a stealth bomber.


:drool: chisel grinds seem to look sharp, if that makes sense. This is sweet ^

Btw congrats on two years.
 
Slicing thin layers off a thick object, a chisel grind with the bevel towards the thin slice is great, because you can sight a straight line off the flat face and the thin slice has little resistance to bending, so it easily moves out of the way. This works well cutting thin slices of veggies, thin wood curls with a paring chisel, or thin chips with a chisel ground axe for truing timbers.

For other tasks such as cutting an apple in half or felling a tree with an axe, a symmetrical grind works best because the lateral forces are equalized and the blade tends to cut straight.
 
Back
Top