Forged Eye Bolt Capacity and Strength Chart to show rated load capacities, proof load and breaking strength of a selected forged threaded eye bolt. The chart is according to ASME B18.15  and ASTM A 489 - 04 standards.

Some important notes from the ASME B18.15:

- Capacities are for carbon steel ASTM A 489 eye bolts, at temperatures between 30°F (-1°C) and 275°F (135°C).

- Loads must always be applied to eye bolts in the plane of the eye, not at an angle.

- Plain eyebolts must be engaged to within one-half turn from the eye end of the threads to get rated capacities given by the calculator.

- Shoulder eye bolts should bear firmly against the mating part; otherwise the rated capacity must be reduced to ones given for plain eye bolts

- To attain the rated capacities given by the calculator, minimum thread shank length of engagement must be as follows:

   -- Steel - 1 thread diameter,

   -- Cast iron, brass, bronze - 1.5 thread diameter,

   -- Aluminum, magnesium, zinc, plastic - 2 thread diameters

- Tapped holes for plain pattern (straight shank) eye bolts are threaded for the full length of eyebolt engagement. Tapped holes for shoulder pattern eyebolts are threaded for the full length with clearance for the unthreaded portion of the eyebolt to allow shoulder seating.

- For through-hole applications, long length eye bolts with shoulder are advised, using a steel washer and nut with the required thread engagement.

Nominal eye bolt size (inches)
Eye Bolt Type


Forged Eye Bolt Capacities
Parameter Value
Nominal Size --- -
Thread Size ---
Eye Bolt Type ---
Breaking Strength, min --- lbf
Proof Load, min ---
Rated Capacity @ 0 deg. ---
Rated Capacity @ 30 deg. ---
Rated Capacity @ 60 deg. ---
Rated Capacity @ 90 deg. ---

Note : Proof load is calculated as 2 times the rated capacity in straight pull (0 degrees).

Note : NR - Not Recommended


Breaking Strength: The breaking strength shall be determined by screwing the lifting eye to the full thread engagement into a block secured in one jaw of the testing machine and held to the other jaw by means of a mandrel passing through the eye.

Proof Load: The load that can be exerted without causing permanent deformation exceeding 0.01 in. (0.255 mm) between prick punch marks at opposite ends of the diameter across the eye.

Rated Capacity: The maximum recommended load that should be applied on the lifting eye. All rated capacities, unless otherwise noted, are for in-line pull with respect to the center line of the eye bolt.



  • ANSI / ASME B18.15 - 1985, Forged Eyebolts
  • ASTM A 489 - 04, Standard Specification for Carbon Steel Lifting Eyes