Mitering

Mitreing (also spelled mitering) is a woodworking and carpentry technique in which workpieces are cut at an angle to form a corner joint. The joint is valued for its clean, continuous outline in frames, moldings, and cabinetry. A miter joint is created when two pieces are cut with complementary angles so they meet at a corner. For a standard right-angle corner, each piece is cut at 45 degrees. When corners are not 90 degrees, the two cuts are complementary and sum to the corner angle. Compound miters may be required for frames or moldings that run on two planes, requiring both a miter angle and a bevel (tilt).

Tools and methods: common devices include a miter saw, a miter box with a backsaw, and a table saw with a precise miter gauge. Accurate miters depend on square stock, careful measurement, and proper alignment of the blade and fence. After cutting, the pieces are joined with wood glue and clamped; fasteners or splines may be added for extra strength.

Fit, finish, and tolerances: gaps are undesirable and corrective steps include trimming, planing, or filling with wood filler. Wood movement due to humidity can affect fit, so allowances or concealed fasteners are sometimes used. Finishing may involve additional sanding and applying paint or stain to conceal the joint.

Applications and limitations: miters are common in picture frames, door and window casings, crown molding, baseboards, and other trim. They provide a neat corner appearance but require careful alignment and precise cutting; poor technique can produce gaps, misalignment, or a visible seam.