SAE J499 makes reference to the shaft dimensions, but only states the following: 'The shaft dimensions depend upon the shape and material of the parts, their heat treatment, and methods of machining to give the required fit. I can not find any references to what the external dimensions of the shaft splines should be. I have a copy of the 28th edition Machinery's Handbook, but can only find dimensional information regarding the internal splines (specifically for broached holes). The slack adjuster mates to the shaft by a 1.5' - 10C SAE spline.
The slack adjuster acts as a lever arm to rotate a shaft which engages the brake pad to the rail wheel.
I'm designing an air brake system for a railroad application which will use automatic slack adjusters which are typically found on over the road trucks/trailers. After several years of referencing this website, I've decided to post a question I haven't been able to find an answer to.
