Piston Groove Top Nut Piston nuts are made of various materials, depending on their strain and purpose. We can manufacture piston nuts for various piston rod sizes and designs. You May LikeMarine Compressor Spare PartsConnecting Rod Assembly BushingReciprocating Compressor Piston RingsPeek Valve PlateCompressor Poppet ValveOil Wiper RingPacking Sealing Ring