My Southbend lathe is very old, thus it has a few issues while running it. One of the things that happens is that the bolts holding the spindle bearings together come loose while using the lathe.
One of my solutions was to use a lock washer to keep them from unscrewing. It worked OK, but wasn’t very pleasing to the eye. so what I did was take some smaller washers that could fit inside the bolt counterbore, and bored the lock washers to fit the correct diameter.
Now I have a much lower profile bolt, and more attractive lathe.
See the pictures below!