Looks like it was a 3mm thick plate. Given that this stuff is half as dense as Aluminum, it's pretty impressive that the grinder behaves like it's cutting the

Looks like it was a 3mm thick plate. Given that this stuff is half as dense as Aluminum, it's pretty impressive that the grinder behaves like it's cutting the most nasty steel (steel is ~3x the density of aluminum and much tougher). If the plate had been aluminum, the grinder would have cut through like it was playdough.