Gehrung

Gehrung is a term used in carpentry and woodworking to describe the method of joining two pieces at a corner by cutting each piece at an angle so they fit together to form a clean, continuous corner. In German, Gehrung specifically denotes the mitre joint, and the process of making mitre cuts is referred to as Gehrungsschnitt. The term is commonly applied to picture frames, moldings, casings, and other trim work.

The basic method involves determining the corner angle and cutting each piece at half of that angle so that the two pieces meet at a precise joint. For a right-angle corner, each piece is cut at 45 degrees. For non-square corners, complementary angles are used. Cuts are made with a miter saw, a handsaw in a miter box, or other accurate angle-cutting tools. After cutting, the pieces are dry-fitted, glued, and often reinforced with nails, pins, dowels, or a spline to improve stability and alignment. A well-executed Gehrung provides a sharp exterior line and hides end grain, presenting a visually seamless edge.

Materials and wood movement: Because wood expands and contracts with humidity, mitre joints can open or loosen if not properly secured or reinforced. They are often glued and optionally reinforced with fasteners or splines to improve resistance to movement, especially in larger frames or trim.

Variants and applications: While the standard mitre joint is symmetrical (typically 45/45 degrees), angles other than 45 degrees are used for irregular frames or architectural trim. Common applications include picture frames, door and window casings, and decorative moldings.

History and tools: Gehrung has long been a fundamental technique in European woodworking, with modern precision achieved through calibrated gauges, miter boxes, and powered miter saws.