Knives are art, and knives are tools. Personally, I don’t draw any lines between.

These two athames are made from O1 steel, or Oil Hardening steel. O1 is a low-end high carbon tool steel, used by machinist for metalworking tools. It will harden to 57 on the Rockwell scale, which is harder than many things. It is used for making knives, but there are so many better choices.

Steels are complicated. The art / science is called “Metallurgy”, and entire careers are built around the atomic structures of metals. Modern steels are created for very specific purposes these days, and knives are definitely one of those purposes. This is not a class in metallurgy, and I know I’m going to take some heat for my opinions here.

Carbon Steels: Steel is just iron, alloyed with less than 2% carbon. Carbon steel is simply a steel in which carbon is the primary alloying element. For some knives it is more important that they are tough, rather than hard. Think Survival Knives, or Machetes. These are knives designed to be abused and hold up to it. Adding Carbon to a steel alloy makes it harder. Making it harder also makes it less flexible.

Damascus Steel: This is a high-carbon steel created by folding one (or more) alloyed steel into another at the forge. It is originally claimed to have started in the medieval city of Damascus, Syria. We now know it was supplied from Southern India or Khorasan, Iran. The idea was to temper the hard and long-lasting alloys with softer and more flexible alloys, so blades would resist shattering. This creates patterns in the steel, which can be beautiful, and are very much sought after today. The patterns in metals are recognized as “Damascus Steel” today and are created with alloys the first Damascus metalworkers could never imagine.

300 Series Stainless Steel: Not all stainless steels are non-magnetic. It is a very weird thing, why some of the stainless steels are magnetic, and some aren’t. Only the 300 series is non-magnetic, and you can’t harden them. If you can’t harden it, why would you make a knife out of it?

Stainless Steels do not stain, or rust because more chromium has been added to the recipe to resist corrosion. It is still, basically a high-carbon steel. Unfortunately, adding chromium takes away toughness, so the Wizards add other elements to the mix to improve performance. Stainless Steel, in order to be considered stainless steel, must have a 13% chromium content. An alloy known as 440 Stainless Steel is common among knifemakers in the United States. It will harden between 58-60 on the Rockwell Scale and isn’t too difficult to shape.

There are amazing alloys used to make knives. Some are very difficult to obtain and are very expensive. Many kitchen knives are made from stainless steel alloys known as AUS-10 and VG-10. Both are Japanese steels, and both are excellent choices for knives. AUS-10 was designed to be tough with good corrosion resistance and edge retention. VG-10 is recognized as having both excellent corrosion resistance and edge retention. It is not quite as tough as AUS-10. VG-10 is nearly twice the cost as AUS-10 as a raw material, and it is much more difficult to shape. This adds significantly to the cost of knives made from VG-10.

Hardness of knives: One of the methods for measuring the hardness of metals is The Rockwell Scale or HRC. The “C” is one of several scales of hardness, in which the Scale C is used in the metals industry. The higher the number, the harder the metal. Hardness is often expressed as 58 HRC or 61 HRC and higher. The nice thing about hard knives is they will hold their edge longer and require less re-sharpening. The bad thing about hard knives is they are less flexible and the harder the edge is, the more likely it is to chip or break. The ultimate hardness of knives are the ceramic ones, and you don’t want to drop one of those. I have been told the Wizards have greatly improved the toughness of ceramic knives, but I have no experience with that. Incidentally, Knyfe’s Edge can sharpen ceramic knives.