Interchangeable Jaw design. Jaw is made of Alloy Steel and its hardness is HRc52-56. The tolerance of matched height is within ±0.01mm. Can combine many sets together for simultaneous processing. Powerful down thrust Leaf-Spring mechanism eliminates workpiece lifting. Mechanical Pressure Booster system enhances efficiency and eliminates losing power. An enlarged double thread master screw rod with high rigidity could make jaws move fast. Base with U-shape design enhances structure rigidity and reduces distortion. Both slideways flame hardened to HRc50-56 can resist wear.