A roller 40 applies a force to {HEAD ~ the peripheral edge} 16 to achieve {TAIL ~ approximately a 60° angle} in a pre hemming step 
to achieve
A roller 40 applies a force to { HEAD ~ the peripheral edge } 16 to achieve { TAIL ~ approximately a 60 ° angle } in a pre hemming step
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH