*NOTE: This is a transcript of my segment from Assorted Calibers Podcast episode 33*
Welcome to Oddball’s corner pocket. This week, I thought I’d talk about the various grinds that are commonly used and why you would use one over the other. Oh, and if you’re into drinking games, you can take a shot every time I say “grind” in this segment. Warning: you may get alcohol poisoning.
First, I think I should probably explain what I mean by “the grind.” While there are some knives where the thickness of the knife blade is the same at the spine as it is where the edge, or bevel actually starts, it’s fairly standard for the knife’s material to thin out at some point, so that it’s thicker at the spine than at the bevel. More material at the spine means that the knife is stronger, but a thinner blade makes it easier to slice through things.
Probably the most common is the saber grind. As the name implies, this was the standard grind with swords like the saber, and is kind of the default for knives. The sides of the blade are roughly parallel with each other at the spine. At some point, the grind starts with a very shallow angle on both sides, and then that angle is changed to a steeper bevel right at the edge.
Like I said, this is pretty much the default, and it’s pretty much the middle ground of all the grinds that I’m going to talk about. There’s other options that are better slicers, but aren’t a strong. Others are stronger, but harder to make and keep as sharp, etc. Honestly, whatever the purpose of the knife, I don’t think you would be going wrong with this grind. It’s also basically the grind that most other grinds are based on.
The one that might be considered more basic is the scandigrind. Basically, a scandigrind is a saber grind that skips out on bevel at the edge of the blade. This results in the angle at the edge being extremely narrow. This makes the knife an excellent slicer that can be extremely sharp. Unfortunately, there are a couple issues with this design. The first being the problem with any knife with a very narrow edge: namely, a more fragile edge. It doesn’t seem to be a huge deal, if the manufacturer knows what they’re doing, but I’ve seen reports of well known knife makers come out with a scandigrind knife that constantly had it’s edge roll on people.
Another issue is that a lot of folks have issues with sharpening this type of grind. It’s not so much that it’s difficult, but that folks don’t understand what they have. If you have one of these knives, and you want to sharpen it, just think of the edge as the entire grind. Sharpening it at more traditional angles will probably actually dull the blade.
This grind’s name comes from the fact that it’s incredible popular with Scandinavian knife manufacturers. In fact, the traditional Finnish Puuko knife uses this style grind. Of course, I can’t mention the scandigrind without mentioning Mora knives, and their excellent budget knives. Some other knife companies that put out good knives using this grind are Helle, and Marttini.
So, if we go back to that saber grind, and push that initial angle all the way to the spine, we’ve got a full flat grind. The advantage of this is that the initial angle can be a little shallower. This makes it a little better at slicing, even though the angle of the actual edge may not change. Since the angle of the grind isn’t much different than a good saber grind on a similar knife, you’re also not losing much strength to the blade. I have been noticing that Spyderco has been putting out a lot of full flat grind knives in the past few years, and some other companies have pushed the initial grind on their saber grinds so far back that they might as well be full flat grinds.
The classic way to have a better slicer than the saber grind is what’s called a hollow grind. With a hollow grind, instead of having a set, straight angle to your grind, the grind is actually a concave curve. This means that the blade thins out very quickly, and stays at that narrow thickness right up to the bevel. I’ve seen this style grind on a lot of kitchen knives, and it does make for excellent slicers. Oh, and the stereotypical old fashioned, fold out razor blade is a hollow grind. The downside is that, since more of the blade is thinner, it can make for a more fragile knife.
On the other side of the coin is the convex grind. The best way to describe this is to think of a spitzer bullet shape. That’s basically the shape down the edge of the blade. That rounded edge means that there’s a lot of metal behind the cutting edge, which means that the edge will be pretty durable. The downside, as you can probably guess, is that it’s a harder grind to get super sharp. The definition of this grind has more to do with the actual edge than the rest of the blade’s construction. So it’s possible to have a convex saber grind, or convex full flat grind, etc. This grind is pretty much the default for axes, meat cleavers, and other blades where they’re used primarily for chopping and will probably hit something hard.
The last grind that I’m going to talk about is the chisel grind. It’s the one grind on this list that’s not essentially based on the saber grind. Simply put, this is the grind that you’d find on a chisel. One side of the knife is completely flat, while the other side slopes down to meet it. This means that the apex of the blades edge is actually off center, and the blade will tend to cut in that direction. If you’re going to sharpen one, other than making sure that the flat side remains flat, you should only sharpen the sloped side. This is generally considered a specialty grind were you’re using the tool to dig into something (like a chisel) or needing the sheering action of something like scissors. There are a couple instances where I’ve seen this grind used in knives. The most common is in very cheap blades, like my Leatherman Micra (by the way, I may rant about sub-par blades on otherwise good multi-tools in the future). Oddly enough, the other use I’ve seen has been in some high-end traditional Japanese kitchen knives. Due to the way a chisel grind cuts, these knives are actually labeled for right hand or left hand use.
I think that just about covers all the common grinds you’ll find, so I’ll stop here. Oh, and if you did decide to do the drinking game and are still upright: grind, grind, grind.