Gather the required materials
Obtain a piston mold or design
Melt the piston material
Pour the molten material into the mold
Allow the material to cool and solidify
Remove the piston from the mold
Machine the piston to exact dimensions
Cut grooves for piston rings
Drill any required pin holes
Inspect for defects and measure tolerances
Install piston rings and wrist pin if needed
Test the finished piston for fit and performance