Inputs
How it is calculated
- Weld cross-section = root gap (G × T) + bevelled groove + reinforcement. For V: O = G + 2 (T−R) tan(A/2), groove area G·T + (T−R)² tan(A/2). The reinforcement is a parabolic segment, 2/3 of base × height (or a triangle, 1/2), as in standard estimates.
- The U joint follows the TWI model: the groove bottom is a radius r (a semicircle at G = 0) and the straight walls are inclined by the angle β.
- Deposited metal (kg) = area (mm²) × density (g/cm³) / 1000 × length (m) × (1 + allowance). Material to buy = deposited metal / deposition efficiency.
- Arc time = deposited metal / deposition rate; total time = arc time / duty cycle (MMA ~25 %, semi-automatic MAG ~45 %, flux-cored ~40 %, mechanised SAW ~40 %, after TWI). Gas = flow × arc time (12–15 l/min for MAG, after TWI). SAW flux ≈ 1 kg per 1 kg of deposited metal (TWI).
- Electrode weights (for the piece count) come from one manufacturer (rutile electrode E 42 0 RR 12). Basic or iron-powder electrodes weigh differently: for orders, check your electrode data sheet.
An informative tool, not a WPS. A welding procedure is specified, qualified and approved according to the standards in force, by competent personnel. The calculations here are engineering estimates made with published formulas; they do not replace the manufacturer data sheet, the material certificate, the qualified procedure or the design check.
Frequently asked questions
How much filler should I buy?
The one in the result, “Filler to buy”, includes the deposition efficiency (for example 59 % for basic electrodes) and the allowance you choose. For reserves, orders or jobs with many repairs, keep a 5–10 % allowance.
Why does the area differ from other calculators?
Some calculators take the root gap only over the root face. Geometrically, the gap and the bevelled groove give exactly G·T + (T−R)² tan(A/2), the formula used here, where the gap is taken over the full thickness. The results were checked against the worked examples published by the Australian Welding Institute and TWI.
Does it work for stainless steel or aluminium?
The geometry and deposited mass work (the density changes), but the efficiencies in the list were compiled for steel consumables. For stainless and aluminium, use your supplier’s efficiency in the “Deposition efficiency” field.
Why is TIG not listed?
TIG consumption depends strongly on technique (length of the rod stub, low currents), and I found no efficiency values in the sources I consulted that I would stand behind. For TIG, use the heat input and t8/5 calculator.
Sources and method
The formulas, tables and verification examples come from public sources, listed below. The standards themselves are paid documents and are not reproduced: I cite the formulas and values published by these sources and, where sources differ, I say so.
- TWI: Calculating weld volume and weight
- Australian Welding Institute: Weld consumable calculator (formulas, worked examples, deposition efficiencies)
- TWI: Welding costs (deposition rates, duty cycles, gas and flux consumption)
- TWI: Typical duty cycles when arc welding
- Gedik Welding: ELIT rutile electrode data sheet (E 42 0 RR 12 / E6013), weights per 100 pieces