What is this tool called and what is it used for?

Question

Can anyone tell me what these are used for? I have a full set that was handed down.

There is NO edge on these at all for cutting and they are too light of a gauge to be snips.

Answer 1

These appear to be snap-ring pliers.

The pins at the nose go into the holes in the snap-ring, then you squeeze to compress the ring to release it from its groove, and flip the lock to hold the squeeze so the ring doesn't expand, rip the pliers from your hand and launch the ring to wherever it is that small parts go to die.

Answer 2

FreeMan's got it, Snap-ring Pliers. heres another example in use:

Answer 3

in the UK these are called circlip pliers.

The points fit inside the ends of a circlip (also called a snap-ring or rotor ring). It is not a cutting tool.

Answer 4

Retaining ring pliers also known as snap ring pliers, circlip pliers, c-clip pliers. They are designed for removing internal or external retaining rings.