Truss Rod is a rod inside the neck of the guitar that is used for adjusting and stabilizing the neck.
Truss rods are needed to to insure that the neck has a profile or bend that allows for optimum playability.
The neck is exposed to mechanical stress. Change in air humidity (local climate) or different string gauges can adds or remove tension to the neck. To counteract that you adjust the truss rod.
NOTE! Over-adjustment of the truss rod can cause damage to the guitar neck, and is not covered under warranty.
Adjustment of the neck
The truss rod is adjustable and used to insure and set the amount and direction of bend in the neck.
- Action Neck Bow And Your Truss-Rod - Ultimate Guitar column by sillybuuger12.