KEVOS® MAKEOS · Fabrication
Fillet Weld Joint Design and Cost
What fillet weld size does this joint need, and what will the weld metal, time and cost be?
Design of a fillet-welded joint loaded in shear on the throat: the throat and leg size required for the load, weld length and allowable throat stress, the leg used after a minimum size for the plate, utilisation, then weld metal mass, arc time, welder time and cost from deposition rate, operating factor, filler efficiency and rates.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Strength | ||
| Load on the weld group | kN | Total load the welds carry, treated as shear on the throat. |
| Total effective weld length | mm | Total effective length of fillet welds sharing the load. |
| Allowable throat shear stress | MPa | Allowable shear stress on the throat for the electrode and code. |
| Minimum leg for the plate thickness | mm | Smallest leg your code permits for the thicker plate joined. |
| Thinner plate thickness | mm | Thickness of the thinner part (a leg larger than this is wasted). |
| Cost | ||
| Convexity and overfill allowance | % | Extra metal for convexity and overfill. |
| Weld metal density | kg/m³ | Density of the weld metal. |
| Deposition rate | kg/h | Deposition rate of the process and wire. |
| Operating factor (arc-on share) | % | Share of the welder’s time with the arc on. |
| Filler deposition efficiency | % | Share of filler bought that ends up in the weld. |
| Welder labour and overhead rate | $/h | Cost of welder time including overhead. |
| Filler price | $/kg | Price of the filler metal. |
Method and formulas
- Required throat = F ÷ (L τ); leg = throat ÷ 0.7071; chosen leg = max(required, minimum), rounded up to the next millimetre.
- Weld metal = leg² ÷ 2 × (1 + excess) × L × density.
- Arc time = mass ÷ deposition rate; welder time = arc time ÷ operating factor; cost = welder time × rate + mass ÷ efficiency × filler price.
- Example: 60 kN on 200 mm of weld needs a 3.5355 mm leg; a 5 mm weld costs about 1.5351.
Limitations
- Uniform shear on the throat; eccentric weld groups need a polar moment analysis.
- Structural welds must be designed to the applicable welding code.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Size and cost the welds on a bracket or frame
- Avoid over-welding that adds cost and distortion
- Quote welding labour and consumables
Who it is for
- Fabrication supervisors
- Welding engineers
- Estimators
What you get
- Required and chosen leg size
- Utilisation
- Weld mass, time and cost
Interpreting the result
- Weld cost rises with the square of leg size: a longer smaller weld is usually cheaper than a short large one.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 1433–1486. 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.
