Fillet Weld Strength Calculator

Estimate static capacity of a single straight fillet weld.

Live concept view — geometry scales with the entered design condition.

PRELIMINARY RESULT

Effective throat4.24 mm

Estimated capacity: 50,904 N

Calculation detail

Formula: Capacity = 0.707 × leg size × effective length × allowable shear stress

Static weld capacity is based on the effective throat area of one straight fillet weld.

Fillet Weld Strength Calculator: operating questions

Does the capacity apply to an eccentric weld group?

No. The model assumes uniform loading of one straight fillet weld. Eccentricity introduces weld-group moment and a nonuniform resultant that requires a separate analysis.

Is 0.707 always the effective throat factor?

It is the geometric throat factor for an ideal equal-leg 45-degree fillet. Actual effective throat and length must follow the applicable welding code and qualified joint detail.

Why must the base metal also be checked?

A weld can have sufficient nominal throat capacity while the connected plate tears, yields, blocks shears or fails by fatigue. The complete load path governs.

Illustrative input values and units
Parameter	Unit	Example
Fillet weld leg size	mm	6
Effective weld length	mm	100
Allowable weld shear stress	MPa	120