May 22, 2012 · 15mm thick brown Ground protection mats 60 tons load capacity To calculate the tons needed for other metals just multiply number times the tons required for punching mild steel: Aluminum (2024-0): multiply x .36 Brass (1/4 hard): multiply x .70 pper (1/2 hard): multiply x .52 High Carbon Steel: multiply x 1.60 A36 Steel (recycled): multiply x 1