The following safety precautions apply to Lifting Pins, Swivel Hoist Rings, Hoist Rings, and Safety Hoist Rings. Also see the Hoist Ring section of the online or print catalog for additional precautions and installation guidelines.
1. IMPORTANT! The load on each hoist ring is not simply total weight divided by the number of hoist rings. The resultant force can be significantly greater at shallow lift angles and with unevenly distributed loads. In the example below:
F = Force on each hoist ring
W = Total weight = 4,000 lbs = 1,814 kg
N = Number of hoist rings = 4
A = Lifting angle
If A = 70º, F = 4000 = 1064 lbs.
If A = 15º, F = 4000 = 3864 lbs.
2. Despite the 5:1 safety factor on hoist rings, never exceed the rated load capactiy. This safety margin is needed in case of misuse, which could drastically lower load capacity.
3. Tensile strength of parent material should be above 80,000 psi to achieve full load rating. For weaker material, consider through-hole mounting with a nut and washer on the other side.
4. Do not allow hoist rings to bind. Use a spreader bar, if necessary, to avoid binding.
5. Do not use spacers between the hoist ring and the mounting surface.
6. Mounting surface must be flat and smooth for full contact under hoist ring. Tapped mounting holes must be perpendicular to the mounting surface.
7. Tighten mounting screws to the torque recommended. Periodically check torque because screws could loosen in extended service. For hoist rings not furnished with screws, mount using only high-quality socket-head cap screws.
8. Never lift with a hook or other device that could deform the lifting ring. Do not use cable assemblies for lifting.
9. Do not apply shock loads. Always lift gradually. Repeat magnaflux testing if shock loading ever occurs.
10. After installation, check that ring rotates and pivots freely in all directions.