Paintstik M and M-10 Marker, 11/16 in X 4.75 in L, Black, M Marks will withstand immediate quenching in water or oil Ideal for welds, ingots, castings, forgings, and other annealed parts M Paintstik withstands 1600 F (871 C) Durable marks will not rub off, allowing for long-lasting identification