Quote Originally Posted by Xmas View Post
The method used in a factory is a special pipe tool with two pins ground or inset to fit the ring notches and a handle at other end. Much less likely to slip when the piece is an inner ring as the pipe is sized to be constrained by the side walls. Similarly on an outer ring the pipe is just sized to clear the ring internally.
A spanner wrench is a poor substitute.
Not damaged anything yet with pliers.
Yes, I'm aware of that. But I'm not going to make a tool like that to use it once, unless it's for something important. I tried the pliers when I was a kid, ruined something, and now use simple improvised tools (for one-time applications) which have yet to leave a mark, much less damage anything. I also file screwdrivers to properly fit the slots in screws.