Traditional Brass Hank-Rivets

ADVANTAGES FOR USING 1/4" HANK-RIVETS
 
With over 40 years as a Toolmaker and Design Engineer, and more than 15 years of machining Red Special guitar parts, we have consistently made many improvements to this beloved guitar, without changing the overall appearance and original concept.
As the drawing shows, there is no difference between the 6.35mm [1/4"] and 8mm [5/16"] Hank-Rivets, except the distance between the flats. All other dimensions are the same.
~~~HISTORY~~~
The reason Brian used the Hank-Rivets he did, was strictly defined by the screw size, specifically, the diameter of the head, required to fit between the clearance slots for the Roller body. This screw, just so happened to be a 6BA x 1/2" cheese-head screw. The only size Hank-Rivets available on the market with the 6BA thread, was 8mm across the flats.
~~~PROBLEM~~~
Installing Hank-Rivets from 8mm [5/16"] stock, requires a 9.52 [.375"] pocket. Having a 2" string-spacing, there is only a 0.63mm [.025"] distance between the pockets. The clearance between the pocket and the Hank-Rivet is just 0.18mm [.007"]. What this means is, if you are the least bit off, your Bridge Blocks will not be aligned properly. If the pockets are off, they will intersect each other and then the tool will walk off due to the interrupted cut. Also, because of the limited clearance, the epoxy has little surface to hold.
~~~SOLUTION~~~
By reducing the distance between the flats from 8mm [.312] to 6.35mm [.250"], allows for more adjustment inside the pocket so that the Bridge Blocks will locate properly even if the pockets are milled off location. The added advantage being there is much more surface area for the epoxy to hold, providing a more secure fit. Again, the only difference is the distance between the flats, but what a difference it makes when it comes to having to scrap a complete body because the pockets are off location, crooked or staggered.