Weldment

Quoting a weldment is quoting labor you cannot see on the print. The pieces are usually simple, plate, tube, a few machined details, and a bill of materials prices them quickly. The money is in everything between the pieces. Prep and bevel, fit-up and tack, the weld itself in passes rather than in inches, and then the consequences, because heat moves metal, and the flatness or bore alignment the print demands after welding often means straightening or machining that happens because of the welding rather than after it.

The argument that decides these quotes is sequence. Machine the critical bores before welding and the distortion eats the tolerance. Machine them after and the weldment has to fit on a machine big enough to hold it, which is a different work center and sometimes a different building. Two floors can quote the same weldment a third apart, both honestly, because they committed to different sequences, and the print settles nothing since prints do not carry process.

Where it costs money is optimism about fit-up and rework. Estimates built from weld length times a deposition rate consistently miss the hours spent making pieces meet before an arc ever strikes, and the grinding and inspection after. These are the low volume, heavy print jobs that get quoted slowly and quoted wrong, and the discipline that fixes them is the same line-by-line traceability walked through in how to quote a machined part, applied to hours instead of seconds. History helps more than a handbook here, because what the last 5 weldments of similar scale actually consumed is the only honest predictor of the sixth.