Grain Runout & Peghead/Neck Fractures

The thin parallel lines shown in the picture represent the grain found in a piece of quartersawn wood.
The dark red lines are of course the shape of the neck.
The majority of the neck is greatly strengthened by the long, relatively straight grain along it's mass, but, when cutting a neck from a single piece of wood the angle necessary at the peghead creates a weakness. Obviously the grain can not run parallel throughout the entire length of the neck when cut from a single slab of wood and this renders the portion of the neck nearest the nut the weakest.

The need for strength along the length of the neck is the reason necks are generally made from quartersawn wood. When wood is quartersawn it provides greater strength by insuring the grain runs parallel with the neck. And while the fingerboard provides additional stiffness and stability, it's important that a neck be able to resist the desire to bow and twist under string tension.
If you can visualize yourself trying to bend and break the neck above it won't take long to figure out where it is likely to snap first. Wood tends to break along the grain line. And of course the greater the angle of the peghead, the weaker it becomes. And yes, Gibson did use quite an angle on their earlier instruments, resulting in pegheads that could break a bit easier. This is why you may notice certain manufacturers using a 2 piece neck which incorporates a joint near the peghead.

  
Typical Peghead Fractures

Choose your back button to return or go directly to

Peghead Repairs