[crystallographic]

Corrections IN CAPS below, as I see the issue:

Originally Posted by vroom

I am making a panel to form 4' long valley. So far I have rolled the bottom of the valley using my e wheel and slick tire set-up. Next I began forming the wings (sides) in my hammer using a linear stretch die. As the panel began to arch down I began to think about the different stretching methods. This is how I understand them:

With regular ROUND CONTACT AREA dies the panel stretches in all directions radially from EACH impact site. LOTS OF RADIAL HITS EQUAL FEWER LINEAR HITS SO LESS TIME IS INVOLVED AND THE METAL IS SHAPED MORE DIRECTLY/EFFICIENTLY.

With linear dies the panel stretches perpendicular / AT RIGHT ANGLES to EACH impact site so less stretching TIME is required to get the valley to arch, IF THE CONTACT AREA IS LONG ENOUGH.

When you are stretching in an e wheel the material stretches parallel to the axle of the wheels (anvils)/ DIRECTION OF TRAVEL so it won't do the job for getting a valley to arch AS EASILY.

I think this is correct but I could use some reassurance.