The covers are used to protect the coil and bobbin from damage due to picking, string snag and other elements that could break the coil. Under the covers are the bobbin assembly which consists of:
6 Alnico magnets sand cast and ground to desired diameter and cut to length.
Top flatwork- made of Vulcanized Fibre or chemically compressed paper in black.
Bottom flatwork- made of Vulcanized Fibre or chemically compressed paper in black and various shades of gray.
Two eyelets for attaching the beginning and finish of the coil, a coil wound from many turns of 42 Formvar insulated magnet wire (older bobbins) and 42 Plain Enamel (newer bobbins)
The pickups are connected to the controls by two 22 gauge stranded hookup wires.
Pickups are very fragile and extreme care should be done when removing or putting covers on. The cover can snag and break the fine magnet wire causing the pickup to fail. Newer covers are made from a pliable molded nylon that can withstand lot’s of picking without fatigue. Earlier plastics used for Stratocaster covers would crack and chip and after early production nylon was substituted for endurance.