parallel

I'm hoping someone here can give me some advice on how to adjust what I've learned are "parallel gibs". I understand adjusting tapered gibs but when I took this mill apart to clean out 50 years of grease pushed through the machine I discovered that it uses this system. It's a US Machine Tool...

Interested in purchasing some Parallel Machine Files. Looking for ones that are approx. 6" to 8" long. My machine will hold up to 3/8" dia. file.

I have noticed that 6" long parallels are commonly available in widths from 1/8" - 1/2" and am wondering if this dimension is a significant parameter for any operation when using a milling vise? Thicker parallels seem attractive from the point of view of being less likely to fall over when...