Tutorial how to make engine part 8

Piston-2
Step 1:
draw shown sketch on the front plane
Step 2:
use cut extrude command
Step 3:
use section view button
Step 4:
open a sketch on the front plane and draw shown sketch
Step 5:
add an axis
Step 6:
use cut revolve command
Step 7:
your piston is ready to use.