Hydraulic Nuts

The application, a Reversing Mill in an aluminum mill, required frequent disassembly and reassembly. Plant Management demanded an improvement in the time required for these operations.

In attempt to improve the cycle times, the plant had made an initial change from torque-tightened nuts to multi-jack mechanical tensioning nuts. However, it was quickly realized that this method, while not requiring the use of large torque wrenches, took much too long to accomplish since tightening the multitude of small jacking screws was a lengthy, tedious process. Furthermore, the method did not ensure consistent and accurate preloads. The final insult was the damage to the coupling faces caused by uneven flange loading

After struggling with this less-than-ideal "solution", the plant finally upgraded to Hydraulic Nuts.

The earlier methods required extensive manpower commitments in personnel and time. It wasn't unusual for the job to require up to two shifts to complete.

As a result of the retrofit to hydraulic nuts, 3 men can complete the job, from start to clean-up in under 40 minutes. The actual time needed to tighten the fasteners is 9 minutes. Bolt loads are now accurate and flange damage has been eliminated.

Hydraulic Nut Application

.... Reversing Mill Upgrade

Fully tightened Hydraulic Nuts - motor side

Conventional Stud ends - mill side

Quick-connect hydraulic harness

Fully tightened Hydraulic Nuts -side view