What are these called and what is their use. Unbranded.

They resemble the 1919 patent   "chain pliers"  [ http://www.datamp.org/patents/advance.php?pn=1320547&id=49637&set=1 ]  which was used for light wire chain like styles  used to suspend 1920s light fixtures, etc.
Yours are obviously newer  -- looks like you can buy a new pair at Home Depot (http://www.homedepot.com/p/Westinghouse-7-in-Fixture-Chain-Pliers-7009900/203811552 )

I have a few pair of these that I use on trap chain and smaller tire chains. They work well.

Quote from: Ken W. on August 25, 2014, 09:58:24 PM
I have a few pair of these that I use on trap chain and smaller tire chains. They work well.

+1
I also have a smaller diameter pair I  use to make oval links in silver I have soldered together.  They work very well.

Chilly

That's it. Thank you everyone. Wife thought it would be good for crabs. It still might be.

Round crabs ;P