What aluminum for bushings?

[Bob Korves]

Bob, this has nothing to do with strength specifications, that's a different ball of wax. This is about thread design, specificly the grip length. Using a standard grade x bolt in this application will result in threads being pressed into the internal bore of both the spacer and the frame bobbin.This application requires a bolt that has a thread length designed to work with a double-shear application.

Threads bearing a load on the inside of a bushing is always a bad idea, shear and double shear applications should have the full fastener diameter (not threads) working in the shear area. Grade 8 has nothing to do with it, that would just be a poor design. I thought perhaps you were spreading the old wives tale that grade 8 bolts are "brittle," which they are not...

 

[crazypj]

Stainless isn't always the best choice. I wouldn't use the alloy for bushing, just for spacers either side. The reason for upgrading a car with tthat type of bearing is to improve handling/'racing' Even though it's only going to save a few ounces total, every little helps

 

[RandyWilson]

All I said was off the shelf grade 8 are designed to be loaded in tension. This is all about thread length vs shank length; nothing to do with brittleness. All I'll say about brittleness is the entire SAE rating system is garbage. If we judged milling machines like the SAE rates bolts, we would be discussing maximum spindle RPM only.


What the OP is doing here is nothing new or unusual. Adapting rod ends to suspension components has been a favorite passtime of all racers and wannabes since the days of McNamara when "cost-plus" DoD contracts flooded the surplus market with cheap rod ends and aircraft hoses. What he wants to do will work just fine as long as the material is stronger than stale peanut butter.

 

[Aukai]

Very interesting reading, the threads will be outside of the bushing, and brackets. The application is straight line acceleration, with street driving. 1/2" holes are used for the brackets as there are multiple mounting holes in each bracket to move the bars to set different geometries for instant center, and anti squat. Bigger holes less/coarser adjustments.