Eye bolts and hoist rings are most used as an anchor point for structural handling equipment, cargo, and lifting:
Eye Bolts & Hoist Rings
Learn about fastening and material lifting techniques using eye bolts and hoist rings. Ensure safe operations with the right equipment for your application.
Large dies and fixtures
Heavy machinery
Mobile equipment
To ensure maximum safety, careful consideration of the application should be made before making a selection.
Eye Bolts
Designed for vertical lifts only, eye bolts are task-specific fasteners often used with additional lifting supplies (such as slings). Lateral or uneven forces can significantly reduce handling load. Additionally, any modification of an eye bolt can also affect handling load.
Fully or partially threaded eye bolt designs offer options for several project priorities. Full threading provides a greater area to disperse the tension for increased grip strength. Partial threading provides more shear resistance, load alignment, and reduced strain (due to the smooth section).
When selecting a solution for your industrial project, consider the conditions. The following materials provide different benefits based on the worksite environment:
- Zinc-Plated: Good rust and corrosion resistance
- Galvanized: Provides better rust protection than zinc
- Alloy Steel: Improved load limits and temperature protection
- Stainless Steel: Best corrosion resistance
Your application also determines if you need fasteners or lifting eye bolts. Fastener styles are ideal for securing an object in place or attaching it to another object, known as static loads. Only products rated for lifting applications can handle dynamic loads. Check the lifting capacity to ensure you select the proper eye bolt for the task.
Hoist Rings
Designed for heavy angular lifts and unbalanced loads, hoist rings have a 180° pivot on the bail and a 360-degree° swivel on the base. This combination allows it to maintain the full handling load at any angle (see formula below to calculate force per anchor point). Different types of hoist rings fit various applications such as:
- Center Pull: Lift from the top of the load, evenly distributing weight
- Side Pull: Lift from the side of the load, adjusting with the pull direction
- Extra-Duty: Also referred to as a swivel hoist ring, offering multi-directional lifting with greater strength and durability
- Safety: Typically used with other equipment, like
Determining Forces on Anchor Points
The force exerted on each anchor point is not simply calculated by dividing the total weight by the number of anchor points. The lift angle is also a significant factor, as lower angles can result in increased force at each anchor point (see below).
F = W/ N sin A
A=65°, F= 4000/ 4 sin 65° = 1103lbs
A=14°, F= 4000/ 4 sin 14° = 4134lbs
Where F= pounds per anchor point in a 4000 lbs., 4-point lift
F = Force on each hoist ring
W = Total Weight (i.e. 4000 lbs.)
N = Number of hoist rings
A = Lifting Angle
Source: American Drill Bushing, March 2004 Hoist Ring