A Good Knife is defined in several ways, One may be a knife that comes from the factory or maker very sharp, another may be a knife that costs very little and holds an edge well, still another might be a knife that looks great and attracts attention.

All these and many more definitions may be given for a good knife, but my definition is this;

1. A good knife must be made of good steel and be properly heat treated and hardened.

2. A good knife must be well made and well finished with materials that will not wear or break with normal use.

3. A good knife will come sharp and hold an edge very well.

4. A good knife will not be overpriced but will be a good value for the price.

With these four points in mind here are some things to look for;

Where is the knife made? Good knives come from all over the world. In general the better knives come from Seki Japan, Germany, USA, Taiwan, Britain, Sweden, Finland, Poland and a few other places.

What will the knife be used for? This question is the most important question you need to answer. If you want a knife to carry everyday for various tasks then a fixed blade hunting knife is a poor choice. Likewise if you want a knife to use while camping to chop, scrape, rip, and slice with then a folding pen knife will not be a good choice.

Each knife design has a function for which it is well suited, and it will work for other functions or tasks but it will have limitations. Do a little thinking before you buy and you will likely make a better choice.

Don't Do These Things With a Knife;

1. Use it as a screw driver. I have done this more times than I should have and 90% of the time I broke the tip off the knife. A knife is not a good screw driver.

2. Use a knife to dig a hole. Again I have done this too many times and 90% of the time I either broke the blade or made large gouges in the edge.

3. Use a knife to pry open something. Here again I have vast experience with this action, the worst was when I tried to pry open a metal outdoor electrical outlet box. The cover was frozen shut with ice. My Al Mar knife was four days old and in two seconds it had lost 1 inch off the tip. I was devastated. But I was also mad at myself because I knew better.

4. Use a knife to cut wire,  sheet metal, Asphalt shingles, etc.... Here a knife may serve well in each of these roles if it has the right steel. But you average pocket or folding knife will only be damaged by doing these things.

5. Use a knife to cut fruit, unless you wash and clean it afterwards. Many good knives become rusty junkers from being used to cut fruits and not washing them up after. The acids in most fruits is quite caustic to steels even stainless steels. So be aware.

What is the right  type of steel or the best steel for a knife?

Well there is no one single answer to this question. 440C steel from a knife company that makes good knives is as close to an all around good knife as you will likely find. But it has downside as well. For one thing it will not hold a super sharp edge for very long. Secondly it will not be real easy to sharpen untill you learn how to sharpen a knife.

440 is the minimum I would accept as a daily carry knife. there are other steels that are as good or even a little better for certain applications, for example 420HC which is used by Buck knives in many of their folders and fixed blades. This is a good steel and when tempered properly will give good service.

Aus-8, Aus-10, Aus-6, these are a step up from 440 steels. These steels if properly heat treated will generally out perform 440, 420, and most other 400 series steels. AUS-4 is an almost exact copy of 440A stainless steel so I exclude it from these upgrade steels.

154CM, ATS-34, D-2, these steels are a step up from the AUS-6,8,10 steels. Each of these when purchased from brand name knife makers will be properly tempered and heat treated and will hold an edge longer and perform better than AUS steels or 400 series steels. ATS-34 and 154CM are almost exactly the same steel. ATS-34 is the Japanese version and 154CM is the American made steel. They are usually indistinguishable from each other. Although some 154CM made from the late 1980's to the mid 1990's was not as good as ATS-34.

VG-10, BG-42, CPM-S30V®, CPM-S60V®,X-15 TN, Powdered Steels from Sweden,  these steels are the top of the line right now in terms of performance and edge holding ability. These steels all cost more and are found only in very high quality knives. These steels will out perform all steels and hold an edge 15-70% longer.

The next super steel is ZDP-189, This steel is incredible in edge holding and hardness. Spyderco, Benchmade and a few other knife companies have made some knives with this steel. Most were prototypes or trial runs. William Henry is the only maker who is using this steel regularly, and of course custom makers will be using this steel. I have been told that the heat treating process for this steel is a guarded secret so it remains to be seen how many custom makers will use this steel.

By the way in tests conducted by Blade magazine ZDP-189 out performed VG-10 by a factor of 10X. That is impressive to say the least. But cost is about 20X higher than VG-10 and manufacturing cost significantly more thus it may be some time before a knife with ZDP-189 steel is affordable for average folks.

I just got a Spyderco Jess Horn limited edition knife with ZDP-189 steel, I have been using the knife for a couple of weeks now and I have a few preliminary impressions. First is this steel is incredible in its ability to hold an edge. I usually test steels by cutting one inch thick corrugated cardboard. You can get this from your local Wal Mart dumpster if it is not illegal in your area to dumpster dive.

Any way I take a new knife and cut this one inch thick cardboard until the knife will no longer cut or until the knife tears the cardboard more than cuts it.

The best knife I've seen until now was a Falkniven U-2 folder that cut over 200" of 1" thick card board. I stopped the test at this point because the blade was so hot from friction that it would burn your fingers. I talking above 200 degrees. Any way I continued the test after a cool down period and the knife ended up cutting another 115" of cardboard, Impressive to say the least, over twice as much as any knife before or after until I got this knife with ZDP-189 steel.

This knife has cut over 400" of 1" thick cardboard so far and the edge is not dull. It is not as sharp as it was right out of the box but it is not dull. I had to stop twice because of the blade getting hot, and I had to stop at last because my hand was cramping. It takes a good deal of pressure to cut cardboard that is 1" thick.

Now the second thing I have noticed about ZDP-189 is it will not take a super sharp edge like VG-10 or AUS-8 steel will. That does not mean it won't take a good edge the factory edge would shave hair easily but when you run a finger over the edge it feels toothy and slightly rough. VG-10 or AUS-8 in contrast has a smooth feel that grabs only slightly. Looking at the steel under a microscope at 60X reveals a structure that is much more coarse than VG-10 or AUS-8.

Also ZDP-189 under this magnification shows a very angular structure as compaired to VG-10 or AUS-8 both of which look more rounded under magnification.

In conclusion ZDP-189 is indeed a super steel, but I don't think most people will like the edgey feel of the blade and the fact that it will literally loose its edge if not used regularly. If you want unbelieveable edge holding ability when working with a knife then this steel is the answer. But if you don't use a knife hard and everyday this steel is not what you will want.