Loss of clamp load after 1,000 cycles. Solution: Check the mating surface flatness. The WUNF 400 requires a surface finish of 3.2 µm Ra or better. Rough surfaces embed and relax over time.
Hydraulic leak in the WUNF 400 actuator. Solution: Inspect the rod seal. The 400 kN force creates significant side loads if the rod is misaligned by more than 0.5 degrees. Realign the mounting brackets. The Future of the WUNF 400 Standard Industry trends indicate that the WUNF 400 is not merely a current product but a growing standard. As machinery becomes lighter (using aluminum and composites) but must handle the same loads, the need for a thread form that distributes stress over a larger area becomes critical. wunf 400
| Feature | Standard UNF 400 | ISO 4762 (12.9 grade) | | | :--- | :--- | :--- | :--- | | Thread Form | Sharp root radius | Metric sharp V | Modified wide radius | | Axial Load Capacity | 380 kN (max) | 400 kN | 440 kN (tested) | | Vibration Loosening | Moderate resistance | Low resistance | High resistance | | Corrosion Protection | Zinc plating (basic) | Black oxide | Electroless nickel | | Price Index | $$ | $ | $$$ | Loss of clamp load after 1,000 cycles