KNIFE KNOW-HOW

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Nowadays there are so many different types of cutlery that making a wise choice can be quite difficult, but many of the offerings are excellent!

The inclined plane upon which the knife, and all other bladed cutting implements, is based is about as simple, in concept, as a tool can be. Throughout the years, however, the first crude edged slicing and chopping stones have undergone an evolution of their own . . . and today's prospective knife buyer is faced with a sometimes overwhelming array of choices. In the color photograph that accompanies this article, for example, there are 36 different knives with a total of 60 blades shown, but that sampling doesn't come close to exhausting even the functional variations in such cutting tools. (As a matter of fact, we were surprised to note that, when we borrowed the selection from a local knife shop, the showcases looked almost as full after we removed the three dozen tools as they had before!)

As perplexing as this diversity may seem, though, it is possible to isolate a few points that the would-be knifeowner should consider always basing his or her final decision upon the specific demands of the job to be done before making a purchase. These include the composition and related properties of the type of steel used (which are determined by the "ingredients" added to the metal and the heat-treating applied to it), the handle material, the shape of the blade, and the method of connecting the handle to the blade.

STEEL

The ideal knife steel would be impervious to corrosion, hard enough to hold an edge for years, ductile (that is, flexible rather than brittle) enough not to break when misused, easy to sharpen to a very fine edge, and (of course) readily workable by a manufacturer. Unfortunately, many of these qualities contradict one another . . . so the perfect steel simply doesn't exist. There are, however, a few types that do stand up pretty well to the amazing variety of demands made on knives.

Steel types are classified according to their chemical makeup, but all the popular, quality knife materials are alloys that contain varying amounts of nickel, chromium, manganese, molybdenum, carbon, silicon, tungsten, vanadium, and other metals. As mentioned above, it's the proportion of each of these components along with the way the blade is heat-treated and tempered that gives a knife steel its individual qualities.

The two most widely used high-carbon varieties are called O1 and D2. The former contains an unusually large percentage of vanadium, is oil-tempered (that's where the "O" comes from), and is often selected for steel-working implements. When it's used to make knife blades, O1 tends to be a bit on the brittle side and corrodes moderately, but it takes a good edge and holds it tenaciously. D2, on the other hand, is a high-chromium steel (it contains 11.5% chromium, just short of enough to classify a steel as stainless) that's air-tempered. Its properties include excellent ductility and the ability to take a very fine edge. Unfortunately, D2 (the "D" stands for die . . . since diemaking is a common industrial application for the metal) corrodes quickly if not properly cared for.