The Questions That Separate a Weldment Shop From a Welding Shop
Two shops can both truthfully say they make machined weldments and be completely different businesses. One welds well and sends parts out to be machined. The other machines well and buys its fabrications in. A third does both and is the one you are looking for.
Here is how to tell them apart without a two day audit.
Start with the chain
Ask one question and listen to the whole answer:
Which of these do you do in your own building: profile cutting, forming, welding, stress relief, machining, inspection, coating.
Every no is a handoff. A handoff is a truck, a queue in somebody else’s shop, a second lead time and a place where accountability blurs when a part comes back wrong.
You are not looking for all yes. A shop that subcontracts galvanising and radiography is normal. You are looking for welding and machining together, and for the shop to be straight about the rest.
The numbers that rule shops in and out
These are quick and they are decisive.
Machine travels. X, Y and Z on the largest machine that would run your part. Not the machine name, the travels. This is the first thing that rules a shop out.
Table load capacity. A 4 tonne frame on a table rated for 2 tonnes is not happening.
Crane capacity and hook height. Often the real constraint. A shop can have the machine and not be able to get the part onto it.
Oven size, if they stress relieve in house. Usable internal dimensions, not the outside of the building.
Largest part welded and machined in the last year. Better than a capability sheet, because it is a fact rather than an aspiration.
The process questions
How do you control distortion on a frame this size?
You want an answer with specifics in it: weld sequence planning, fixturing or a modular table, positioners, prebending, controlled heat input. A shop that says “our welders are good” has not thought about it. Compare against the distortion control guide.
How much machining stock do you want left on the faces?
A real weldment shop has a view, and it varies by part. Somebody who says “whatever the drawing says” has not been burned yet, or is not the one deciding.
Do you stress relieve before machining, and how do you decide?
Covered in the stress relief guide. You want to hear about weld volume, restraint, material removal and tolerance, not a blanket policy.
How do you locate the part for machining?
Fixture, machined datum face, laser tracker alignment. The answer tells you whether they machine weldments routinely or occasionally.
The paperwork questions
Procedures and qualifications. Which WPS covers this material, thickness and joint, and are the welder qualifications current and in range. See the WPS and qualification guide.
Certificates and scope. Which certificates, issued by whom, expiring when, and covering what scope. The scope matters more than the certificate.
Inspection. Which NDT methods are in house and which are bought in, and who holds the qualifications.
Dimensional reporting. What they will provide, measured how, and referenced to which drawing revision.
Material traceability. Mill certificates per heat, and how the heat number follows the plate through cutting and into the finished part.
The fifteen minute floor test
If you can visit, look for six things:
- Fixtures or a modular table, not parts propped on blocks and wood.
- Positioners in use, so welds are being made in the flat position.
- Stainless kept physically separate from carbon steel, with its own tools and abrasives, if they do stainless.
- Written weld sequences at the station, not in somebody’s head.
- Machined parts stored properly, faces protected, not stacked on concrete.
- The place is organised. It is a crude signal and it correlates well.
The commercial questions people forget
Who owns the fixture? On a repeat programme this matters when you want to move the work or add a second source.
What happens if the first part is out of tolerance? Ask before, not after. The answer tells you how they think about risk.
What is the real lead time, broken down? Cut, fit, weld, stress relief queue, machining, coating, inspection. A single number hides where the schedule risk actually is.
Will you quote the fixture separately? On repeat work this usually saves money across the programme.
Red flags
- Cannot give machine travels from memory or in an hour.
- Says no fixture is needed on a large frame with tight geometry.
- Has no opinion on machining allowance.
- Quotes very fast on a complex part without asking a single question.
- Certificates exist but nobody can say what the scope covers.
- Will not say which steps are subcontracted.
The fast quote with no questions is the one that most often turns into a re-quote later.
Where we fit
We ask shops these questions at registration, record the answers including the travels and the crane capacity, and match your part against them. We do not audit shops and we do not certify anyone. The introduction is ours, the decision and the qualification stay yours.
Send your RFQ and we will match it with shops that answer these questions well.
Frequently asked questions
What is the single most useful question to ask?
Which of these steps do you do in your own building: cutting, welding, stress relief, machining, inspection and coating. The pattern of yes and no tells you where the handoffs are, and handoffs are where schedule and accountability go missing.
Should I visit the shop before ordering?
For a significant or repeating part, yes. Fifteen minutes on a floor tells you things no document does: whether parts are fixtured or propped on blocks, whether stainless is kept separate, whether positioners are in use and whether the place is organised.
Is a large shop always safer than a small one?
No. A small shop that makes parts exactly like yours every week will often beat a large one where your part is an oddity. Size matters for capacity and for crane and machine envelope, not for competence.
Need a quote for this part?
Send the drawing. We match you with up to 3 shops that weld and machine it in house, and we reply within 24 business hours.
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