The scarf joint in wood
In woodworking, there are two distinctly different categories of scarf, based on whether the joint has interlocking faces or not. A plain scarf is simply two flat planes meeting on an angle relative to the axis of the stock being joined, and depends entirely on adhesive and/or mechanical fastening (screws, bolts, etc.) for all strength. Hooked, keyed, and nibbed scarfs are some of the many example of interlocking scarfs, offering varying degrees of tensile and compressive strength, though most still depend on mechanical fastening to keep the joint closed.
The plain scarf is not preferred when strength is required, so it is often used in decorative situations, such as the application of trim or molding. The use of modern high-strength adhesives can greatly increase the structural performance of a plain scarf. Scarf joints are used on mass production guitars where the headstock angle dips far back
|Major guitar brands have signature headstocks that make their guitars or guitar series easily recognizable. An unwritten law of the guitar industry allows copying of overall guitar body designs, but no major brand copies headstock designs. As seen in a section below, even "copied" at the first glance designs retain clear visible changes in dimensions, proportions of elements, etc, so it is almost always possible to tell a major brand of a guitar by looking at headstock.|