What is an eye bolt?
If you make a screw that ends in a loop at the head instead of a hex, round, oval etc shape end you have an eye bolt.
How are eye bolts used?
Eye bolts are commonly used to attach cables or slings to objects. In a household you might see eye bolts attaching a wire or string to the back of a frame to allow the frame to hang from a nail or hook on a wall.
This type of eye bolts are often called wire eye bolts (also referred to as bent or turned eye bolts). They are used for light duty applications, and should not be used for angular loads. You might find a wire eye bolt with machine screw threads or as a lag screw style (wood / sheet metal screw threads).
Drop forged eye bolts. Forged eye bolts, with machine screw threads, are significantly stronger than wire eyes and are available in larger sizes for eminence and assembly applications.
In maintenance, Drop forged Eye bolts are commonly used to aid in lifting of machinery.
For heavy lifting, Drop forged Eye Bolts are typically offered in both shoulder style and non-shoulder styles.
Only shoulder eye bolts should be used in a lifting operation when the rope or sling will be used at an angle. Angled lifts significantly reduce the capacity of any eye bolt. You need to refer to the manufacturer's specifications before attempting to make a lift. No greater load should be applied to an Eyebolt than the Rated Capacity listed. If the angle of the lift will be over 45 degrees do not use eye bolts. Safety Swivel Hoist Rings are recommended for such applications.
