When installing an eyebolt or swivel hoist ring in a tapped hole, how much thread engagement is required?

The requirement for thread engagement when installing an eyebolt or swivel hoist ring is crucial for ensuring the safety and integrity of the lifting operation. A thread engagement of 1.5 times the diameter of the bolt is considered the minimum to properly distribute the load and prevent failure due to fatigue or shear forces. This level of engagement provides adequate support and strength, allowing for proper load-bearing characteristics and minimizing the risk of stripping the threads in the tapped hole.

In practical terms, this means that if the bolt diameter is, for example, 1 inch, the minimum depth of thread engagement required would be 1.5 inches. This guideline is in place to account for variations in materials, thread conditions, and dynamic loads that can occur during lifting operations. Proper thread engagement helps ensure that the eyebolt or hoist ring remains securely fastened and can safely handle the intended loads.