Traditional 6BA Brass Hank-Rivet Mtg. Set

Advantages of Using 1/4" Hank-Rivets
With over 40 years of experience as a Toolmaker and Design Engineer, and more than 15 years dedicated to machining Red Special guitar parts, we have continuously enhanced this iconic guitar while preserving its original design and appearance. As shown in the drawing, the only difference between the 6.35mm (1/4") and 8mm (5/16") Hank-Rivets is the distance between the flats, with all other dimensions remaining identical.
History
Brian originally chose the Hank-Rivets based on the screw size required for the design. Specifically, the screw needed to fit between the clearance slots for the Roller body. The screw used was a 6BA x 1/2" cheese-head screw, and the only Hank-Rivets available with a 6BA thread had an 8mm width across the flats.
Problem
Using Hank-Rivets made from 8mm (5/16") stock requires a 9.52mm (0.375") pocket. With a 2" string-spacing, this leaves only 0.63mm (0.025") between the pockets. The clearance between the pocket and the Hank-Rivet is just 0.18mm (0.007"). This tight tolerance means that even a slight misalignment can cause the Bridge Blocks to be improperly positioned. Misaligned pockets may intersect, causing the tool to deviate due to the interrupted cut. Additionally, the limited clearance provides minimal surface area for the epoxy to adhere securely.
Solution
Reducing the distance between the flats from 8mm (0.312") to 6.35mm (0.250") allows for greater adjustment within the pocket, ensuring proper alignment of the Bridge Blocks even if the pockets are slightly off. This also increases the surface area for the epoxy, resulting in a more secure fit. While the only change is the distance between the flats, this small adjustment significantly reduces the risk of scrapping a guitar body due to misaligned, crooked, or staggered pockets.