Made of premium steel, high hardness and long durability. Heavy duty nut splitter which is designed for safe removal of corroded or damaged nuts without damaging bolt threads. Easy to use: Just rotate the nut splitter bolt to work on the target nut. You may prepare a wrench help you to do this work. Nut Splitter Bolt Diameter: 0.47inch/12mm(#1), 0.55inch/14mm(#2), 0.71inch/18mm(#3), 0.82inch/21mm(#4). Suitable Removing Nuts Range: 9~12mm(#1), 12~16mm(#2), 16~22mm(#3), 22~27mm(#4). Widely Used: Suitable for splitting and removing rusty broken, damaged, corroded, stuck nuts. Just rotate the nut splitter bolt to work on the target nut. You may prepare a wrench help you to do this work.