?????

[thinkbackwards]

Can anyone tell me what these are for? They are 12 inches overall. Have duckbill jaws and are made of cast aluminum.

[Dollar Bill]

They appear to be pliers used in the jewelry making industry - The lack of serrations on the duckbill would allow you to hold flat stock for polishing without marring the surface. There is a similar pair on eBay: https://www.ebay.com/itm/265778573370 It appears the seller does not recognize intended purpose either

[mklotz]

They look a bit like a body-piercing clamp...

https://www.amazon.com/Body-Piercing.../dp/B07PHLTTK8

but those are usually plastic and disposable, not aluminum.

The choice of aluminum is probably key to determining the purpose. After all, how many hand tools have you seen made of cast aluminum?

[CharlesWaugh]

Parts removal pliers for removing parts from plastic injection molds.
The aluminum is softer tan the mold, so no damage to the expensive mold occurs.