Slings and Eye Bolts
Many types of equipment either come with Eye Bolts or are fitted with Eye Bolts for lifting purposes.
|1)||Eye Bolts are marked with their thread size, NOT with their rated capacities. ONLY Swivel Hoist Rings are marked with their rated capacities.||5)||Use only eye bolts which are designed for LIFTING. Do not use “no name” products. You cannot determine the steel grade by “feel” or “look”.|
|2)||If you assume that a standard eye bolt has the same angularity strength loss factor as your sling, YOU ARE WRONG.
A sling used at a horizontal angle of (for example) 45° retains 71% of its VERTICAL capacity.
A standard eye bolt used with that same 45° horizontal angle retains just a mere 30% of its VERTICAL capacity. This is important if you shackle an eye bolt into a sling and assume that if the VERTICAL sling capacity matches the VERTICAL eye bolt capacity you have a safe sling system. Nothing is farther from the truth!
|6)||Use Shoulder (Machinery) Eye Bolts for angled lifts.|
|7)||It is BEST to use Swivel Hoist Rings for EVERY angled lift. They adjust to any sling angle by rotating around the bolt and the hoisting eye pivots 180°.|
|8)||For a further discussion on how to safely use eye bolts please refer to our CROSBY® catalogue, or ask your local UNIROPE representative for advice.|
|3)||NEVER, and that means NEVER, rig a sling through eye bolts. You severely increase the stress on the eye bolt and the bolt can break.||With Regular
(non Shoulder) eye bolts, use a spreader bar to keep the lift angle at 90° to the horizontal.
|4)||Although eye bolts can be used down to a 30° horizontal angle, we DO NOT RECOMMEND this practice. The strength loss of an eye bolt approaches 75% of vertical rated capacity, and any even slight decrease in horizontal lifting angle may break the bolt.|
|Never reeve slings through eye bolts. This alters the load and the angle of loading.|
|We recommend that eye bolts only be used at a horizontal angle greater than 45°. Sling strength at 45° is 71% of vertical sling capacity.
Eye bolt strength at 45° horizontal angle drops down to 30% of vertical lifting capacity.
|Use swivel hoist rings for rigging. They self adjust to any load angle and are clearly marked with their capacity and recommended
|At 45° lifting angle eye bolts have just 30% of their rated VERTICAL capacity. A sling (any type) used at the same 45° angle retains 71% of its vertical capacity.|