I have the current project which is part of a critical operation the steps as follow,
1- An overhead crane will lift an Injection Mold (The device that can make plastic parts ). Its weight is 38000 Ibf.
2- The connection part is what we need to analysis the stress on it .in other words, to see what is the typical screws size that can assist in the lifting process.
3- The connection parts are consist of Swivel Hoist Ring, thick plate and bolts. The bolts are tightened to the injection mold (tighten torque value of the bolts is neglected ). I have attached the mechanical properties for the bolts. In case we need to use the torque.
4- The thick plate is positioned in the middle of the injection mold. No pattern for the bolts, some times is a different pattern.
5- because of the crane is an overhead crane, so there is no angle in the chain of the crane that connected to the Swivel Hoist Ring. The crane will lift the injection mold vertically and place the injection mold on the track vertically too.
*Seating torques for alloy steel calculated in accordance with VDI 2230, “Systematic Calculation of High Duty Bolted Joints,” to induce approximately 120,000 PSI in the screw threads through 0.500-inch diameter, and 115,000 PSI over 0.500-inch diameter.