DFS shrinking jaws test samples

All samples are 18swg and the shrunk surface is 1" wide.

dfsshrinksample1.jpg from left to right aluminium, brass, copper, steel, stainless steel showing single impression. 
dfsshrinksample2.jpg from left to right aluminium, brass, copper, steel, stainless steel showing worked surface after multiple impressions.
dfsshrinksample3.jpg show brass and copper closeup of worked surface.