مسمار سداسي

Support both ends of the shaft on V-blocks and measure the radial runout of each journal with a dial indicator. Runout exceeding 0.05mm/m indicates bending. Slight bending can be corrected by cold pressing; if bending is large or surface cracks exist, replace the eccentric shaft.

Bolts must be completely replaced when thread damage, cracks, excessive elongation (usually exceeding 0.2% of original length), severe surface corrosion, or one overload fracture occurs. Never reuse high-strength bolts that have been overloaded.

Tie rod fracture is mostly caused by excessive spring tension, overload impact from tramp iron in the feed, thread fatigue damage, or wrong material. It is recommended to use 42CrMo quenched and tempered tie rods, regularly check spring tension, and install tramp iron protection.