Blades - Often made of a blend of carbon, which holds sharp edges longer, and chromium, a stainless steel alloy that retards rust and corrosion. The blade should have a finely ground, satiny surface and should taper evenly from the handle to the tip, and from the back of the blade to the cutting edge.
Bolsters - The collar or shank (thick band of metal) at the point where the blade meets the handle.
Handles - Rose-wood is the preferred because it is extremely hard and has no grain, which helps to prevent splitting and cracking. Impregnating wood with plastic protects the handle from damage caused by continued exposure to water and detergents. Some state codes require that plastic handles be used in butcher shops, because they are considered more sanitary than wood. Grease adheres more closely to plastic than it does to wood.
The handle should fit your hand comfortably. Manufacturers typically produce handles that fit a variety of hands. Spend some time holding the knife. A comfortable fit will improve the ease and speed with which you work. A poor fit can result in fatigue, or cramping. People with very small or very large hands should be sure that they are not straining their grip to hold the handle. Some knives are especially constructed to meet the needs of left-handed users.
Rivets - Metal fasteners to secure the tang to the handle.
Tangs - The end of the blade that extends into the handle is called the tang. It should run the entire length of the handle for better balance and strength. Molded handles do not have a full tang but rather form a seamless, permanent bond around the tang.
Types of Blades
Carbon steel - Carbon steel blades make a better edge than either regular or high-carbon stainless steel, but they tend to lose their sharpness quickly. The carbon steel blades tend to discolor when they come in contact with high-acid foods, such as tomatoes or onions. For some chefs, this sharp edge makes up for the discolorations that occur with age. Wash and thoroughly dry between use and before storing. The metal is brittle and can break easily under stress.
Stainless steel - Has better corrosion resistance than carbon steel because the carbon in the steel is replaced with chromium to allow for the overall resistance of corrosion. While it has better stain resistance, the blades ability will be to hold an edge is lessened. Stainless steel is much stronger than carbon steel and will not discolor or rust. It is very difficult to get a good edge on a stainless steel blade, although once an edge is established, it tends to last longer than that on a carbon steel blade.
High Carbon Stainless steel - more durable, tougher, can hold a better edge and has better performance than stainless steel blades. The one drawback is corrosion resistance, which will be more likely to set in and is critical for a blades long term performance. Once rust or any other form of corrosion is exposed to a blade then the ability to sharpen or keep an edge diminishes.
Hollow-ground - Made by combining two sheets of metal. The edges are fluted or beveled.
Taper-ground - The blade is forged out of a single sheet of metal and has been ground so that it tapers smoothly from the spine to the cutting edge.
Ceramic knives - Lighter and harder than steel, (Two of the producers are Kyocera of Japan and Boker of Germany.) The knives may hold an edge for years, but because there's not a reliable method for at-home sharpening, the knife may need to be sent back to the manufacturer for that purpose.