Plan groove setup with unit options, tolerances, and practical defaults for crews. See gap ranges, volume, and filler estimates before you weld every time.
| Thickness | Land | Bevel (per side) | Process | Electrode | Root Opening (auto) | Top Width |
|---|---|---|---|---|---|---|
| 10 mm | 1.5 mm | 30° | SMAW | 3.2 mm | ~3.0 mm | ~12.8 mm |
| 16 mm | 2.0 mm | 35° | FCAW | 1.2 mm | ~3.7 mm | ~21.2 mm |
| 6 mm | 1.0 mm | 25° | GTAW | 2.4 mm | ~1.9 mm | ~6.1 mm |
1) Recommended root opening (auto mode)
g = clamp( f · (0.60·d + 0.10·t) + p + (sh% · t), 0.5, 12 )
2) Groove geometry (single-V approximation)
depth = t − a
topWidth = g + 2·depth·tan(β)
area = ((g + topWidth)/2) · depth (+ topWidth·reinforcement)
Angles are per side. The groove area is approximated as a trapezoid, optionally plus a simple reinforcement allowance. This is intended for estimating fit-up and filler needs.
Root opening is the controlled gap at the joint root that lets heat and filler reach the root line. Too small a gap can trap slag, limit penetration, and raise repair rates. Too large a gap can cause burn-through, excessive reinforcement, and higher filler consumption. Fit-up discipline is especially important on field joints where tack sequence, handling, and temperature changes can shift the gap during installation.
For many carbon-steel groove welds, crews often plan root openings in the 1.5–4.0 mm range for thinner members and 3–6 mm for thicker sections, depending on bevel, land, and process. This calculator provides an estimated gap plus a min–max window using your fit-up tolerance. Use that window for go/no-go checks with feeler gauges and for communicating acceptance limits to fitters and inspectors.
The bevel angle controls how fast the groove opens as depth increases. A larger angle increases top width and groove area, which increases filler volume and time. The land (root face) reduces groove depth; increasing land can prevent burn-through but may require more root opening or more heat input to achieve penetration. The tool models a single-V groove as a trapezoid to estimate area and volume quickly.
Different processes tolerate different gaps. Processes with stable arc control and higher deposition efficiency typically support tighter planning, while others may need more opening to maintain root fusion under variable conditions. The calculator applies a practical process factor for recommended opening and uses an assumed deposition efficiency to estimate filler weight. These are planning values, not procedure qualification results.
The penetration input is a planning allowance that nudges the recommended opening higher when the goal is full root fusion. Shrinkage allowance adds a percentage of thickness to account for gap closure from tack welds, thermal contraction, or restraint. For long joints, small closures add up; a 1% allowance on 16 mm thickness adds 0.16 mm, which can matter when tolerances are tight.
Fit-up tolerance turns one target number into an inspection-friendly band. If your tolerance is ±0.5 mm and the target is 3.0 mm, the acceptable window becomes 2.5–3.5 mm. This supports consistent QC notes and helps prevent “creep” during tacking. When you see gaps trending toward the upper limit, adjust tack spacing, backing strategy, or heat input planning before welding starts.
The calculator estimates groove area, then multiplies by joint length to produce volume. For millimeter units, volume is shown in cm³; for inch units, volume is shown in in³. Filler weight is estimated from steel density (about 7.85 g/cm³) and a process efficiency factor. This helps forecasting consumables for a run of joints and comparing how a bevel change affects overall welding time.
Measure root opening at multiple points along the joint, especially near tack welds and at starts/stops. Record the target and the tolerance band on fit-up sheets, then attach exported CSV or PDF results to inspection packages. If the joint is out of range, correct alignment, replace tacks, or re-machine bevels rather than “forcing” the weld. Better planning reduces repairs and improves schedule reliability.
No. It is a planning estimate based on your inputs and general fit-up practice. Always follow the approved welding procedure specification and any project inspection criteria.
Use manual mode when your procedure fixes a specific gap, when backing or consumable inserts dictate the opening, or when you are matching a shop standard already proven in production.
Top width affects access for the root pass and how much filler is needed for fill and cap. Larger widths often increase time and cost, even if penetration is easier.
Groove area increases rapidly with angle because the sides spread as depth increases. A few degrees can add significant volume over long joint lengths, increasing wire or electrode usage.
Include reinforcement when your work scope expects a consistent cap height, or when estimating worst-case filler usage. Leave it at zero for groove-only comparisons and quick planning.
Base it on tooling and access. Shop fit-up may hold ±0.5 mm or better; field fit-up may need ±1.0 mm. Tighter bands often require better jigs and more verification points.
No. It supports planning and documentation only. Procedure qualification tests, inspection records, and experienced welding supervision remain the authority for acceptance and performance.
Better openings mean cleaner roots, faster passes, safer builds.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.