# Every seam found in the model. Every size read from the drawing.
URL: https://arcnm.io/platform/weld-detection
Language: en

Where two parts of an assembly touch, ARCNM finds the joint and measures the seam. It types the joint as tee, butt, lap or edge. The weld symbols on the drawing (ISO 2553) confirm the joint is welded and set its throat. A joint that nothing confirms is shown, but not priced as a weld.

## 5 seams in the sample bracket, 904 mm in total
The engine's joints for the bracket ARC-1022, read from the STEP file alone. Beside each, what the drawing states for it. Without a symbol, the throat defaults to 0.7 × the thinner plate.
| Joint | Type | Seam length | Plates | Throat from the model | On the drawing |
| --- | --- | --- | --- | --- | --- |
| Base plate – Web | tee | 280 mm | 10 / 10 mm | a 7.0 (0.7 × t) | a5 all round |
| Base plate – Gusset 1 | tee | 156 mm | 10 / 8 mm | a 5.6 (0.7 × t) | a4 both sides |
| Base plate – Gusset 2 | tee | 156 mm | 10 / 8 mm | a 5.6 (0.7 × t) | a4 both sides |
| Web – Gusset 1 | tee | 156 mm | 10 / 8 mm | a 5.6 (0.7 × t) | a4 both sides |
| Web – Gusset 2 | tee | 156 mm | 10 / 8 mm | a 5.6 (0.7 × t) | a4 both sides |

## Seam length from the model, throat from the drawing
- Contact patches between bodies are found on the 3D model. Each joint is typed from how the plates meet: tee, butt, lap or edge.
- Seam length runs along the patch. Plate thicknesses and the gap come with it.
- The throat comes from the drawing's ISO 2553 symbol, a weld table, or 0.7 × the thinner plate. A leg size is held between 1 and 25 mm, because it enters the weld volume squared.
- Intermittent welds (n × l (e)) are priced at the deposited length, not the full edge. An all-round symbol without a length takes the closed loop from the model.
- Seams on the drawing are priced first. The model fills only what the drawing leaves out.

## It does not invent a weld
A joint is priced as a weld only when the evidence says it is welded. That evidence is a weld symbol or a weld table on the drawing. In the sample run, with the STEP file alone, all 5 joints were found and none was confirmed. ARCNM priced fixturing and tacking and flagged the weld for review instead of guessing a deposit. With a welding station in your costing environment, the weld is also timed in house. Arc welding is timed by deposition rate, laser welding by travel speed. The cross-section comes from the ISO 9692 joint preparation. The in-house time is compared with your subcontractor's price per metre.

## FAQ
**Can ARCNM find welds without a drawing?**
It finds the joints and measures every seam from the 3D model. It prices them as welds once a weld symbol or a weld table confirms it. Until then the seams are listed and the calculation is flagged for review.

**Which weld symbols does ARCNM read?**
ISO 2553 fillet, square butt, V, double-V, bevel, spot, seam and plug welds. It reads throat a or leg z, length and intermittent runs. It also reads ISO 4063 process numbers such as 111, 135, 141, 52 and 21.

**Is the weld priced in house or bought in?**
Whichever is cheaper. With a welding station in your costing environment, ARCNM times the seam in house. It also prices the seam at your subcontractor's rate per metre. It uses the cheaper route and names it. Without a welding station, the seam is bought in.