KEVOS® MAKEOS · Strength
Lifting Lug Design (Plate, Pin and Bearing Checks)
Is this pinned lifting lug strong enough for the sling load: net tension, tear-out, bearing and pin shear?
Check of a plate lifting lug with a pin or shackle: the load per sling leg from the total load, number of legs, sling angle and a dynamic factor, net-section tension across the hole, shear tear-out beyond the hole, bearing of the pin on the plate, double-shear stress in the pin (as the bolt and pin shear tool), utilisation of each against your allowables and the hole clearance.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Total load lifted | kN | Total weight of the load (as force). |
| Sling legs sharing the load | Number of sling legs that share the load (use fewer if the slings may not share evenly). | |
| Sling angle from vertical | ° | Angle of each sling leg from vertical. |
| Dynamic factor | Factor for snatch and acceleration during the lift (your value from the lifting code). | |
| Lug plate thickness | mm | Thickness of the lug plate at the hole. |
| Distance from hole centre to the plate edge (in the load direction) | mm | Distance from the hole centre to the plate edge in the direction of the pull (the edge radius for a round-ended lug). |
| Hole diameter | mm | Diameter of the pin hole. |
| Pin diameter | mm | Diameter of the pin or shackle pin. |
| Allowable tensile stress | MPa | Allowable tensile stress of the plate (your design value). |
| Allowable shear stress (plate) | MPa | Allowable shear stress of the plate. |
| Allowable bearing stress | MPa | Allowable bearing stress between pin and plate. |
| Allowable shear stress (pin) | MPa | Allowable shear stress of the pin. |
| Largest hole clearance | mm | Largest clearance you accept between hole and pin (larger clearance concentrates bearing stress). |
Method and formulas
- Load per lug F = W × dynamic factor ÷ (legs × cos θ).
- Net tension σ = F ÷ [(2R − d_h) t]; tear-out τ = F ÷ [2 t (R − d_h ÷ 2)].
- Bearing σ_b = F ÷ (d_p t); pin in double shear τ_p = F ÷ (2 × π d_p² ÷ 4).
- Example: 200 kN on 2 legs at 30° puts 144.34 kN on each lug; the highest utilisation is 80.188%.
Limitations
- Simplified lug checks; lifting codes add out-of-plane loads, cheek plates and weld checks.
- The lug weld to the structure needs its own check.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Check a lifting lug on a fabricated frame
- Size a padeye for a new lift
- Review a lug when sling angles change
Who it is for
- Structural engineers
- Rigging supervisors
- Fabrication supervisors
What you get
- Design load per lug
- Net tension, tear-out and bearing stresses
- Pin shear and utilisations
Interpreting the result
- Tear-out usually governs short lugs: increase the edge distance before the plate thickness.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 1535, 1720–1735. Topic reference; no source tables or recommended settings are reproduced.
WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
Open the Lifting Lug Design (Plate, Pin and Bearing Checks) calculator
