What are the rubber washers used for on the pickup height adjustment on old Fender guitars?
It is basically a amber surgical tubing made from a gummed-rubber that had been commonly used for medical purposes. It has measurements of 1/4 OD, 1/8 ID with a wall thickness of 1/8 . It is now commonly used with many types of exercise devices and commonly seen on sling shots. I like using the rubber tubing for the height adjustment around the screws as it helps reduce the unwanted vibration or feedback that can occur with a metal spring and it helps cushion the pickup in the pickguard or plates such as in a Telecaster. The metal springs are usually made from spring steel that can pull the magnetic field from the pickup and feedback at higher pre-amp or amplifier volumes.
