Complete Guide to Eye Bolts

Author：Solidlink Hot：

Eye bolts are one of the most common lifting anchor points, but they are also one of the most misused. Loading an eye bolt at the wrong angle or in the wrong direction can distort it and reduce its capacity. This guide explains eye bolt types, ratings and safe use.

What Is an Eye Bolt?

An eye bolt is a bolt with a looped eye at one end, used to attach a sling, hook or rope to a load or structure. The threaded end fixes into wood, metal or concrete, and the eye takes the lifting load.

Types of Eye Bolts

Forged eye bolt with shoulder: a shoulder seats against the surface to resist bending, used for lifting.
Eye screw: a wood-threaded eye, for lighter anchoring in timber.
Pad eye: a welded or bolted plate with an eye, used where a fixed anchor point is needed.
Ring nut: a nut with a ring, used on threaded studs.
U-bolt: a U-shaped bolt with two threaded legs, used for clamping and anchoring.

How Eye Bolts Are Rated

Eye bolts are rated by working load limit (WLL), but the rating depends on the load direction. A forged eye bolt loaded in line with its axis can carry its full WLL. Loaded at an angle, its capacity drops significantly. Never side-load an eye bolt unless it is designed and rated for it.

How to Choose the Right Eye Bolt

Choose a forged eye bolt with a shoulder for lifting.
Match the thread to the material: machine thread for metal, wood thread for timber.
Pick the WLL for your maximum load and load angle.
Choose galvanized or stainless steel for outdoor or marine use.

Safe Use

Tighten the shoulder firmly against the surface so the eye cannot bend. Keep the load in line with the eye, and use a swivel or shackle if the load direction changes. Inspect for cracks, bent eyes or worn threads before each lift.