Bolt-on neck is a method of guitar (or similar stringed instrument) construction that involves joining a guitar neck and body using screws as opposed to glue as with set-in neck joints. The term is a misnomer, introduced mostly by Fender whose guitars traditionally had "bolt-on necks". Real bolted joints (i.e. using bolt coupled with a nut) are uncommon in guitar production. However, at least one aftermarket manufacturer offers a replacement for Fender neckplates and screws which uses captive nuts — embedded in the guitar body by means of an external self-tapping thread — and M4 bolts. This is claimed to permit a higher fastening torque than ordinary woodscrews, and hence a better coupling between neck and body.
This method is used frequently on solid body electric guitars and on acoustic flattop guitars. In the typical electric guitar bolt-on neck joint, the body and neck cross in horizontal plane, the neck is inserted in a pre-routed "pocket" in the body, and they are joined using 4 (rarely 6) screws. As screw heads damage the wood and could put extra stress on it, typically a rectangular metal plate or a pair of metal plates are used to secure the joint and re-distribute the screw pressure evenly. Such a plate is usually criticized for making playing on top frets uncomfortable, so, manufacturers sometimes employ some kind of more intricate method to hide a metal plate, smooth the angles and make access to top frets easier. However, a visible metal plate is usually considered as a part of "vintage" style and they are a popular place to emboss manufacturer's logos, stamp out serial numbers and put other artwork.
The typical acoustic guitar bolt-on neck as popularized by Taylor guitars includes threaded inserts in the heel of the neck. Bolts inserted through the neck block of the body from inside the instrument attach the neck to the body.
Luthiers and guitar players cite both advantages and disadvantages of bolt-on neck construction. Note that most of these views are highly subjective and relative. It is not easy to measure most of the claims objectively or even compare objective factors, as guitars differ considerably.
Some sources differentiate bolt-on and bolt-in neck construction.
The difference is that bolt-on neck involves constructing a protruding flange that fits inside a routed pocket in guitar body. Then neck is secured inside this pocket using screws that run perpendicular (at right angles) to the surface of guitar. A bolt-in neck doesn't need to have such a flange inside guitar body, and screws or bolts run parallel to the surface of guitar, entering the back of the heel.
Usually (but not always), in bolt-in variant, a neck pickup is mounted directly on the extended neck wood underneath it, not on the guitar body. This has been referred to as "direct coupling", because the pickup is mounted on the neck and not the body, in other words, directly coupled to the neck, and is considered superior by some in terms of tone.
Bolt-in neck is used in acoustic guitars on regular basis, but on electric guitars it is somewhat rare, harder to produce, but it is considered superior by some in terms of sound and playability. However, given a relative uncommonness of bolt-in necks in electric guitars, most luthiers call both neck joints "bolt-on".
Typically cited advantages of bolt-on neck include:
Typically cited disadvantages of bolt-on neck include:
Notable manufacturers of guitars with bolt-on necks include: