The notation “Piston, 1.0mm – HCC3912050” indicates a piston with a 1.0mm oversize. This means that the piston is designed for use in an engine with cylinder bores that have been machined or worn beyond standard specifications, requiring a 1.0 millimeter oversize piston. Oversize pistons are commonly used during engine rebuilds when the cylinder walls need to be enlarged to accommodate new pistons and restore proper functionality. The 1.0mm oversize specification denotes the additional diameter of the piston compared to the standard size.

Specifications: