Notched Straightedge — Lutherie Encyclopedia

Notched StraightedgeType: toolA precision straightedge with notches that straddle frets, used to evaluate neck relief and check neck angle on guitars.## Description A notched straightedge is a precision-ground steel or aluminum bar, typically 24 to 25 inches long, with shallow notches cut along one edge at intervals matching standard fret spacing. The notches allow the straightedge to sit directly on the fretboard surface, straddling the frets, so it reads the actual surface of the neck rather than resting on fret tops. The opposite edge is a standard straight reference. ## Use in Lutherie The notched straightedge is used to assess neck straightness and relief during construction and setup. By placing the notched edge on the fretboard, the luthier can see whether the neck surface is flat, has a forward bow (relief), or has a back bow. It is also used to check the neck angle relative to the bridge position before gluing the neck to the body, which determines the string action geometry. The non-notched edge can be used as a standard straightedge for checking top flatness and other surfaces. ## Selection Guide Stew-Mac and LMI offer notched straightedges sized for both steel-string and classical guitars. The straightedge must be precisely ground; any bow or twist in the tool renders it useless. Aluminum straightedges are lighter but can bend if dropped, while steel versions are more durable. Ensure the notch spacing matches the scale length you build. Budget 25 to 60 dollars. ## Tips - Handle the straightedge carefully to avoid nicking or bending it. Store it in a protective sleeve. - When checking neck angle, place the stra…