If you are refering to lifter-liner bolt removal machines, they have advanced today by specialty suppliers, not SAG mill mfgrs. You should query these machine mfgs for knowing the latest techniques.

Speed is essential to minimize mill downtime. There are options in how this is accomplished, including mill liner designs.

Bolt design has been badly understood and caused failure in liners due to overdesigning and overtorquing which in turn causes overstress in liners as they wear and have reduced sectional modulii. ■