Author: Joe Talmadge firstname.lastname@example.org Last Modified: December 1998
II. Plain vs. Serrated: The Conventional View III. Plain vs. Serrated Re-thought
IV. What Should I Carry?
V. Thoughts On The Partially-Serrated Blade
There's been a jump in recent years in the popularity of serrated edges, and there's often confusion as to when a serrated edge is advantageous, versus when a plain edge is advantageous. The question comes up often in rec.knives.
For our discussion, we'll need to talk about what we're doing with the knife. Think about what you can do with a knife: you can shave, slice, slash, saw, hack, chop, etc. For our purposes, we'll divide all knife uses into two very broad categories:
Push cuts: The main cutting is done by pushing the edge through the thing-to-be-cut. For example, when you shave, you push the edge of the knife through your beard. When peeling an apple, you push the edge under the skin of the apple. When chopping wood, you try to push the edge into and through the wood.
Slicing cuts: The cutting action is substantially done by dragging the edge across the thing-to-be-cut. When you slice meat or a tomato, you drag the edge across the tomato as you cut through it. Slicing and sawing are examples of slicing cuts.
II. Plain vs. Serrated: The Conventional View
In general, the plain edge is better than the serrated when the application involves push cuts. Also, the plain edge is superior when extreme control, accuracy, and clean cuts are necessary, regardless of whether or not the job is push cuts or slices.
In general, the serrated edge will work better than the plain edge for slicing cuts, especially through hard or tough surfaces, where the serrations tend to grab and cut the surface easily. Some of the cutting power of the serrated edge is due to its format alone; thus, even a dull serrated edge knife will often perform competently at slicing jobs. The serrated edge gets its slicing ability from a number of factors. The high points on the serrations will touch the material first, and this gives those points higher pressure per area than if the same pressure was applied to a plain blade; this allows the serration to puncture more easily. In addition, serrations are normally chisel-ground into the blade, which means they are thinner (and thus cut better) than the comparable plain blade.
The plain edge will work better for applications like shaving, skinning an apple, skinning a deer. All those applications involve either mostly push cuts, or the need for extreme control. Serrations work really well on things like tough rope or wood, where the serrations bite through quickly.
Generally, the more push cuts are used, the more necessary it is for the plain edge to have a "razor polished" edge. A knife edge becomes more polished when you move to higher and higher grit stones. Generally, 1200-grit is considered polished; a 6000+ grit Japanese water stone would polish the edge further.
One interesting case is cutting a tomato. In theory, you can just push a blade through a tomato, so a razor polished plain edge would work fine. However, the tomato is soft, and unless your plain edge knife is very sharp, the tomato will simply squish when you start pushing. You can (and many people do) use a slicing motion with your plain blade, but if it's even a little dull it won't cut well and it may not even break the skin. Use a sawing motion with a serrated knife (even a dull one), and your tomato will slice fine.
You will read about test after test where the above view is confirmed. That is,