The Casinjac cylinders are mounted to the cylinder mounting plate by placing a 2" - 8 UN stud ( some earlier models used had 12 UN threads on the bottom of the cylinder through a 2" hole with a 3.125" counterbore drilled to accomodate the stud nut 3" OD with spanner wrench holes. Counterbore cavity should be filled with an appropriate grease to prevent corrosion of the stud and nut threads.
The nut should be checked periodically for tightness and integrity as while the strengths of the nut and stud are more than adequate to support the loads they support corrosion and other factors could affect their function. If examination reveals damage to the threads immediate action should be taken to correct the problem.