lot of industrial 5/8'' trunion/poppet machine clamps

Lot of six industrial trunion clamps with a black oxide finish. We've been told that these are called "poppets", but are not sure. They measure 1.5" long overall, 0.75 long and 0.65 diameter on the body. The cross hole is 0.30 in diameter. The threads are 3/8". These all have wing nuts.