We have tried different types along with different Mfg's, the one that works best for us is a solid pnuematic type called soft tuff. I have a DP50K in the shop today with a drive tire with molten metal damage, down the center of the tire is burned out and missing. I have watched the operators run through spilled molten aluminum, it sticks to the tire and continues to burn. We pay about $1,200 for two 300-15 soft tuff's.