What is the wrench size for truss rods?
We have one type of wrench. L-shaped Allen wrenches are using, and the diameter is 4mm. (caution: not 3/16″) • Temperature and Humidity Changes in humidity are the greatest danger to your guitars. High humidity can even cause wood to swell and distort. Low humidity is also bad for guitars. You should have a room humidified to 45%~48%. Especially don’t allow it to get cold and then warm too quickly. Our guitars built in factories with sufficient humidity control.