Depending on the application, cutting tools range from simple hand saws to complex carbide-tipped reamers. There are a number of machining services which can be referred to as cutting, including drilling, grinding, boring and reaming. This is because these services all involve the removal of material from a work piece, which defines cutting. Typically, the term “cutting tool,” however, indicates the part of a machine that comes in contact with the material and performs the actual removal of the material. A drill or augur bit, or a circular saw blade, therefore, would be a cutting tool.
In order for a cutting tool to work on a material, it must meet a few requirements. First and foremost, it must be harder than the metal to be cut. In fact, certain cutting tools incorporate a brazed carbide tip insert in order to provide cutting action on exceptionally hard materials. Carbide is not used exclusively due to its brittleness and expense—a tool must also be able to withstand cutting forces without breaking. Lastly, the tool’s shape must be designed to allow its cutting edge to remove material from the work piece. This removal is accomplished by a movement of tool or material. Other popular materials for cutting tools are steel, ceramic and diamond. In general, all cutting tools fall under three categories: single-point, multi-point and abrasive tools. Essentially, single and multi-point tools refer to the number of cutting edges. A band saw, for instance is a single-point tool, since it has one cutting edge. A drill bit or reamer, on the other hand, has a number of cutting edges, and is therefore classified as a multi-point tool. Abrasive tools, as you might expect, include various types of grinding wheels. These remove chips using a mass of compact, cemented abrasive grains. Water jet and laser cutting machines do not use a part that comes in contact with the work piece, and therefore do not use a “cutting tool.”
Many cutting tools are controlled by computer numeric control (CNC) machines, which are capable of creating incredibly precise and detailed shapes. Operating on a given set of instructions, many of these machines can utilize cutting fluids and lubricants to prevent overheating and reduce strain, perform multiple cutting processes, and repeat any given task as many times as necessary. Long run cutting operations, however, usually employ standard or custom engineered machines due to cost concerns.
