Early Fender guitars and basses use a “cross screw” nut for truss rod adjustment, which has two slots arranged in a cross pattern.
Sonora, CA (January 4, 2012) — CruzTOOLS announced their new GrooveTech Truss Rod Drivers for vintage-style truss rod nuts on guitars and basses.
Early Fender guitars and basses use a “cross screw” nut for truss rod adjustment, which has two slots arranged in a cross pattern. Cross screw fasteners achieved popularity during the early 20th century because a second slot was provided if the first became damaged. Early Fender designers may have seen this as beneficial, especially since modern hex drive nuts weren’t yet available.
In addition to older instruments, many vintage reproduction guitars and basses make use of cross screw nuts. Adjustment of cross screw nuts presents several problems. Nuts are made of unhardened steel with very narrow slots, so standard screwdrivers don’t fit properly. An 1/8” (3mm) wide blade might have the only tip thin enough to fit into the slot, yet slots are 3/8” (9mm) wide. Thus, only a portion of the slot is contacted with damage likely after several uses. Since only half of the nut is typically exposed, proper adjustment requires neck removal. Achieving correct neck relief (curvature) may take several attempts, resulting in a tedious process. Musicians are therefore tempted to adjust without removing the neck. Truss rod tension is relatively high, so the amount of resistance during adjustment may be considerable. These high torque demands combined with poor slot contact on unhardened steel can easily chew up nuts, which is clearly evident on many vintage instruments.
Recognizing these problems, CruzTOOLS developed two new screwdrivers for adjustment of vintage-style truss rod nuts. Both employ a special tip profile that allows firm fit into cross screw nut slots. Oversized handles provide a confident grip, and long shafts ensure easy access to the nut. Tips are manufactured to precision tolerances using heat-treated chrome vanadium alloy for high strength.
Despite the extra effort, necks with cross screw nuts should generally be removed for adjustment. The GrooveTech Standard Truss Rod Driver has a 9mm wide tip that will contact the entire nut slot for quick and damage-free adjustment. The Standard Driver should be a tool box staple for any technician or musician with cross screw equipped instruments.
For those who prefer making minor adjustments without neck removal, CruzTOOLS developed the GrooveTech Cheater Driver. Its 4mm wide tip is designed for a secure fit into the slot, and operation is aided by a large handle with extra-long shaft. Successful adjustment requires a nut in good working condition and following recommendations provided by CruzTOOLS.
Suggested retail for each screwdriver is $14.95.
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