Norwolf Uni-Back™ Norwolf Uni-Back™ The essential tool for holding thru bolt nuts in place. UNI-BACK™ STUDMATE™ HYDRAULIC PUMPS NORWOLF Uni-Back™ Benefits: Fits on all standard API flange applications. ½ turn of screw releases all torsion. No more hammering off of knocker wrenches. Custom configuration available. This is the heading Custom configuration available.