A flitch is a beam of wood cut from a tree. Some flitches are resawn into thinner pieces for use in various woodworking projects, and many are cut with very sharp blades into extremely thin slices called veneer. Flitches are also used in construction to make flitch beams.
Flitch beams are made by sandwiching a piece of steel, called a flitch plate, between two flitches, usually of some species of pine. This produces a very strong beam that can be used in areas where a long, unsupported beam is necessary. The standards for making these beams are very exacting and account not only for the length, width, and thickness of the wood and steel members used, but also for the species of wood used. For instance, a flitch beam made of California redwood is slightly stronger than an identical beam made with lodgepole pine. This makes the construction of flitch beams very labor-intensive, though, and for that reason, when more varieties of engineered lumber, like laminated veneer lumber (LVL) became readily available in the late 20th century, flitch beams' popularity declined.
The flitches used to make flitch beams are straight sawn from pine logs; that is, the logs are simply sawn into long beams of equal thickness by cutting the log along its length. Plain sawing, though, distorts the appearance of the wood's grain, with some of the grain lines appearing widely spaced and others more narrowly-spaced. Woodworkers generally prefer more uniform grain patterns, though, and there are other ways to cut logs, such as quartering them around the center of the log, that will produce boards and veneers with more uniform grain patterns.
Veneers are very thin layers of wood, often no thicker than 1/8 inch (three millimeters), “peeled” from flitches by very sharp blades. Veneers are usually cut from hardwoods such as oak, cherry, maple, or more exotic species. Adhered to the more plain pine wood used to build the case of a piece of furniture or cabinetry, they give the surface a more interesting or attractive appearance. Using a saw to cut veneers is discouraged by woodworkers both because the process will blur the detail of the grain and also because a great amount of wood is lost to the saw. Veneers are generally sliced from flitches by veneering machines, which pass their blades through the stationery flitches, shaving off very thin slices.