A utility knife (also known as a Stanley knife or by various other names) is a cutting tool used in various trades and crafts for a variety of purposes. Designed to be lightweight and easy to carry and use, utility knives are commonly used in factories, warehouses, and other situations where a tool is routinely needed to open boxes, packages, or cut through tape or cord.
Such a knife generally consists of a simple and cheap holder, typically flat, approximately one inch (25 mm) wide and three to four inches (75 to 100 mm) long, and made of either metal or plastic. Some use standard razor blades, others specialized double-ended blades as in the illustration. The user can adjust how far the blade extends from the handle, so that, for example, the knife can be used to cut the tape sealing a package without damaging the contents of the package. When the blade becomes dull, it can be quickly reversed or switched for a new one. Spare or used blades are stored in the hollow handle of some models, and can be accessed by removing a screw and opening the handle. Other models feature a quick-change mechanism that allows replacing the blade without tools, as well as a flip-out blade storage tray.
The blades for a utility knife come in both double and single ended versions, and are interchangeable with many, but not all of the later copies. Specialized blades also exist for cutting string, linoleum and other purposes.
Another style is a snap-off utility knife that contains a long, segmented blade that slides out from it. As the endmost edge becomes dull, it can be broken off the remaining blade, exposing the next section, which is sharp and ready for use. When all the individual segments are used, it is thrown away or a replacement blade is inserted. This design was introduced by Japanese manufacturer Olfa Corporation in 1956 as the world's first snap-off blade and was inspired from analyzing the sharp cutting edge produced when glass is broken and how pieces of a chocolate bar break into segments.
Fixed blade versions, about the size of a pencil, are used for handicrafts and model making and are best suited for cutting thin, lightweight materials; the specialized handle and blade allowing for cuts requiring a high degree of precision and control.
A style that is often used for cutting open boxes consists of a simple sleeve around a rectangular handle into which single-edge razor blades can be inserted. The sleeve slides up and down on the handle, holding the blade in place during use and covering the blade when not in use. The blade holder is designed to expose just enough edge to cut through one layer of corrugated fiberboard, to minimize chances of damaging contents of cardboard boxes.
Utility knives have changed a lot since their original introduction with new safety features and designs that increase the effectiveness and safety of the person using the tools. The Klever Kutter, Klever Koncept and Klever X-change are three newly introduced designs that have proven to eliminate user injury while greatly reducing the risk to both the user and the products being opened.
