Gear Grinding Arbour: Rotary Engineering Corporation: Hydraulic Expanding Clamping Solution: Gear Grinding Mandrel / Arbour: Gear Shaving mandrel: Hydraulic Clamping System: Expanding Work Holding For Gear Work holding Technology. We Rotary Engineering Corporation Manufacturer of Hydraulic Expanding World-Class Clamping Solution For Modern CNC control based operated machines. Application oF Rotary CONCENTRIC Mandrels/Arbour. • Turning parts • Milling parts • Grinding parts • Gear production machines • Testing and inspection process • Balancing machines