Each 316 Hilti mechanical bolt including Petzl hanger cost about R50 , the drill bits are R175 .
Each 316 Hilti mechanical bolt including Petzl hanger cost about R50 , the drill bits last for around 20 holes .
Each 316 Hilti mechanical bolt including Petzl hanger cost about R50 , the drill bits are R175 and last for around 20 holes .