Back in my shop days I used a wide variety of lock ring tools...except for the pliers type. Never really like those.

My go to tool was the Hozan and another with a 'swing/pivoted' but I cant remember the name of that one. In my opinion the Park tool are not designed properly, they're too thinwhich decreaces surface area with the ring and they're too tall which causes them to rock of the ring.

The big key to the Hozan/Park style tool is to grind a flat where the arms meets the ring.

1. Hook the tool onto a lock ring as if you were going to remove it.
2. Mark the tool with Sharpie where the body of the tool makes contact with the lock ring.
3. Grind a perpendicular flat where you made the mark.