Custom metalwork fails in two places. It fails in the workshop, when a process is chosen badly. It fails in the paperwork, when two businesses believe they agreed different things. A purchase order is the document that removes the second kind of failure, and it asks for nothing more than attention.
On standard parts the order is simple, because the part number carries the specification. Custom work has no such shorthand. The order has to describe the item, the material, the finish, the quantity, the inspection expectations and the handling of changes. Anything left out will be filled in by assumption, and the assumption may not be yours.
The order should name the part in a way that survives time. A drawing number plus a revision is the strongest identifier, because it points at one specific geometry. A description alone is weaker, because descriptions are interpreted differently by different readers, and a photograph is weaker still, because it carries no measurements.
Where a project started from a sample, say so on the order and refer to the drawing the engineer produced from it. That single reference connects the order to the measurement that actually governs production, and it prevents a later discussion about which version of a part was intended.
If the shipment will contain more than one variant, list them separately. Left and right versions, different finishes and different assemblies can look identical in a crate, and a clear line on the order is what makes the packing list meaningful.
Material belongs on the order by grade rather than family. A drawing that carries material and special requirements can be built from directly, but the order should still restate the grade so that the confirmation and the order agree with each other. Where a buyer has chosen from a catalogue organised by material, they can simply quote the item as listed, which is why a reference like our material-indexed pages is useful to cite in writing.
Finish should be described in the same terms the workshop uses. Brushed, polished, satin and coated finishes are produced by different sequences, and a vague instruction such as a good finish gives the workshop no way to know where to stop. If the finish matters, name it. If it does not, say that instead.
Tolerance deserves a sentence even when nothing unusual is required. Naming the drawing as the tolerance reference, and flagging any feature that is critical, tells the shop where to concentrate measurement effort. Features that carry no note are, fairly, treated as ordinary.
The order should state the quantity clearly enough that a shortfall is visible on arrival. It should also say whether partial shipments are acceptable, because a shop that assumes a single shipment and a buyer who expects two will both be surprised.
Delivery terms should name the destination and the method, and they should identify who is responsible at each stage of the journey. Packaging instructions belong here as well, particularly for thin-wall tube and flat panels, which are easy to distort in transit.
Where the buyer intends to order again, mentioning it here changes how the job is set up. It is a legitimate thing to say on a purchase order, and it carries no downside. Silicone and hose items are a good example, because a repeat requirement affects how a hose order is consolidated and identified for later reference.
The order should describe what will be checked and what the buyer will do with the result. If dimensional inspection takes place against the drawing, say so. If the buyer expects the parts simply to arrive and be fitted, say that too, because it changes how the shop documents the job internally.
Acceptance terms matter most when something goes wrong. A clear statement of what the buyer will inspect on arrival, and how quickly a concern will be raised, keeps a small problem small. The alternative is discovering a discrepancy during fitting, weeks after the crate was opened, when the trail has gone cold.
Where a closed or pressurised assembly is involved, the order can call for the test that was agreed at sample stage rather than inventing a new one. Consistency between the sample record and the production order is the whole point of writing either down.
Custom projects change. A dimension is adjusted after a trial fit, a bracket is moved, a finish is reconsidered. The order does not need to prevent that. It needs to define how a change is recorded, so that both sides know which revision is live at any moment.
Most workshops will accept a change by email against a specific drawing. The risk is an instruction given verbally to someone on the shop floor, which then becomes a real change with no document behind it. Writing the rule into the order removes that risk in one sentence.
Where tooling has already been made, a change may have physical consequences, and the buyer should understand that before giving the instruction. A customization process built around tooling and samples is inherently sensitive to changes arriving late, which is why the sequence starts with negotiation rather than with cutting metal.
Some terms are so commonly omitted that they are worth rehearsing deliberately. Nobody intends to leave them out, but on a busy day the order goes out with the essentials and the context missing.
Any welded assembly that joins existing parts needs its end connections described. Any part that is visible needs its finish noted. Any part that will be fitted by someone other than the buyer needs the information that person will require. A custom intercooler installation, for instance, usually involves several people between order and road, and each of them reads the paperwork differently.
The rule of thumb is simple: if a detail would cause a delay to explain later, put it on the order now. Written context travels further than remembered context, especially across an ocean.
A purchase order for custom metalwork does not need to be long. It needs to be complete on the points that cannot be recovered once production starts.
Tigindustry works from drawings that carry dimensions, material and special requirements, and falls back on a measured sample only when no drawing exists. Our fabricated parts range shows the kind of assemblies that flow through that route, the titanium components section shows the material-led variant, and buyers who start from a known application can short-circuit several questions by quoting a vehicle-based reference. A complete order is the most valuable engineering work any buyer will ever do.
