Biseau

Biseau is a term used in woodworking, metalworking, stone, glass, and related crafts to denote a bevel or chamfer—an inclined surface produced by removing material from an edge or corner. The purpose of a biseau is to soften a sharp edge, improve fit between parts, reduce stress concentration, or create a specific decorative or functional profile. It is typically formed by grinding, planing, filing, milling, or sanding an edge until it lies at an angle to the adjacent face.

In technical usage, a chamfer is a particular type of biseau: a shallow, flat bevel along a corner, commonly at 45 degrees. A bevel, more generally, is any edge or surface that is cut at an angle other than perpendicular to the face, and it need not be limited to a corner. The exact angle and width of a biseau can vary depending on function, material, and tooling.

Applications of biseau span several trades. In carpentry and cabinetry, beveled edges create joints, picture frames, or decorative moldings. In metalworking and welding, bevels prepare joints for welding or assembly. In glass and gemstone work, beveled edges produce decorative or reflective effects and reduce chipping at edges. In stoneworking, bevels are used for sight lines, polish transitions, and joinery. The term emphasizes the inclined nature of the edge, regardless of its specific angle or width, and is often used interchangeably with bevel in English-language technical contexts, especially when discussing French-origin terminology.