Here's Your Free Report on Knife Sharpening
My name is Ken Wolfe and I've been
making handmade knives for about
Why won't my knife stay sharp?
It seems like a universal problem and it doesn't have to be.
The most important item for a sharp knife is one word: Steel. Well that and the proper Heat treat. Most commercial knives are made from some kind of stainless steel because it looks nice and it's rust resistant. Usually 440 Stainless. You noticed I said resistant. Even stainless steel will discolor or even rust but not anything like carbon steel. The problem is that carbon steel is the best steel for a knife because it's the carbon in the steel that helps keep the edge and also aids in hardening. That's the simple explanation.
So, now you have a choice to make. Having a pretty shiny blade or one that stays sharp longer. Of course you have to care for the Carbon Steel Blade. A little oil or I wax the blade to keep rust or tarnish away.
If you can find a stainless like ATS34 in a commercially produced blade, you can have the best of both worlds. Almost. ATS34 is arguably the best stainless around (Now we have many more like CPM S30V and CPM S35VK ) and you can find some commercially made knives that use it but, of course, it is more expensive. Oops, I forgot 154CM which is very similar Lots of custom knifemakers use it and 440C. ( Updated See Above ) The C stands for high carbon and 440C is a very good all around stainless for less money.
Of course, there are many other things that are involved in a blade's sharpness or ability to hold an edge. The proper hardening process, toughness and angle the blade is ground at to name just a few. We knifemakers have been arguing for ever about the proper angle for the edge (from 18 to 30 degrees) but the most universally accepted angle is around 22 degrees. Naturally, the lower the number the thinner the edge and the weaker it is so if you want to shave with it, thinner is better. Ever see a thick razor blade? A thin edge will "roll over" more easily. So I recommend 22 degrees for an all around edge.
Another subject to argue about is how to
properly sharpen your knife. If you
can properly keep the angle the same on both
sides by hand, a series of stones
are great for sharpening. Expensive Japanese
or Arkansas stones are said to be
the best but the new diamond hones are
pretty good. Most people need some help
keeping the angle the same on both sides so
many companies have come out with
sharpeners with "fixed angles" using
tungsten carbide, ceramic and diamond
cutters in their sharpeners; and you pull
the blade through them or pull the
sharpener along the blade. Other more
expensive units clamp the knife at the
proper angle to pull across a stone or
diamond hone. Some have a series of
grits ending with one to "polish" the edge
and remove the burr created while
sharpening. Of course if your secondary edge is Convex then you need a Soft Back with Wet or dry paper. A mousepad works well as does Leather on a wood board.
The tungsten carbide cutters remove a lot of metal but sometimes you need to get the edge back and need to remove metal to do that. As you might expect, it's best not to let it get that bad. I prefer diamonds or Arkansas Stones, but that's just my personal preference. They all work pretty well.
Edge shape is another arguable point.
convex, flat or concave (or hollow)
grinds. Hollow ground is the most prevalent
and is a weaker edge than convex
(Moran Grind) that I prefer and only found
in custom made knives.
Well, I hope we've helped a little with your sharpening problems. If you enjoy Handmade Custom Knives, please visit my Site at www.wolf-mountain.com
Click here to see a Great Arkansas Stone Sharpener Kit with a built in Angle at around 20 degrees total!