When to Keep Weldment Work In House and When to Buy It
Most manufacturers that use welded structures end up with some capability in house and buy the rest. The question is where the line sits, and it moves as the product and the volume change.
What in house actually costs
The visible cost is the welder and the machine. The full cost includes:
- Floor space and crane capacity, which are usually the binding constraint.
- Fixturing, which is per part and does not transfer.
- Qualified welding procedures and the supporting qualification records, plus welder requalification on a cycle.
- Inspection capability, or a relationship with somebody who has it.
- Consumables, gas, extraction and the maintenance on all of it.
- Idle capacity. The big one. A welding bay sized for peak demand is under-loaded most of the year, and that cost is real whether or not anybody books it to the job.
None of that argues against in house capability. It argues against sizing it for the peak.
What outsourcing actually costs
Also more than the invoice:
- The drawing package has to be genuinely complete, because the shop cannot read your mind. See the RFQ checklist.
- Supplier qualification and audit time, which is yours and stays yours.
- Lead time you do not control, particularly plate availability and subcontracted queues.
- Freight, which on heavy weldments is a serious line.
- The cost of being wrong about a supplier, which is a scrapped frame and a missed date.
Where the line usually sits
A pattern that works for a lot of manufacturers:
Keep in house: prototypes, urgent repairs, small brackets and anything where the turnaround matters more than the unit cost. Short queue, no procurement cycle, immediate feedback into design.
Outsource: large structures that need machines you do not own, anything needing an oven you do not have, volume runs that would occupy your bay for weeks, and anything requiring a certification scope you do not hold.
The deciding questions are usually physical rather than financial: does the part fit on your machine, does it fit under your crane, can you stress relieve it.
The capability that changes the answer
One capability shifts the line more than any other: welding and machining in the same building.
A shop that welds, stress relieves and machines a part itself controls the whole sequence. It decides the machining allowance knowing what its own welding does, and it can adjust between operations. A part split between a welding shop and a machine shop is managed across a handoff, with a truck and a queue in the middle and an argument available if the part comes back out of tolerance.
If you have that under one roof, keeping the work in house is worth more than the cost sheet suggests. If you do not, outsourcing to a shop that does is worth more than the invoice difference.
That is also why we match on it specifically rather than on welding capability alone.
Making the outsourced version work
If you buy it, three things decide whether it goes well:
- Specify properly. Weld sizes, quality level per joint, inspection scope with a weld map, machined features with datums on machined faces. Most outsourcing failures are specification failures wearing a supplier costume.
- Choose on capacity numbers, not on capability claims. Machine travels, table load, crane capacity, oven size. See how to vet a weldment supplier.
- Treat the first article as a real gate. Full dimensional report against the drawing revision, before the rest of the batch exists.
A short rule
Keep in house what is fast, small and iterative. Buy what is large, heavy, documented or needs a machine you do not own. And when you buy, buy from somebody who owns the whole sequence rather than from somebody who owns half of it.
Send a drawing and we will match it with shops that weld and machine in house. Free for buyers, and we take nothing from the order.
Frequently asked questions
What is the real cost of keeping weldment work in house?
Not just the machine and the welders. Floor space, crane, fixturing, consumables, qualified procedures, welder requalification, inspection capability, and the cost of that capacity sitting idle between jobs. The last one is usually the largest and the least counted.
Does outsourcing lose you control of quality?
It moves control from supervision to specification. Instead of watching the work, you specify it properly and inspect the result. That is a different skill and it is why an outsourced programme lives or dies on the quality of the drawing package.
What should never be outsourced?
Anything where the process itself is your competitive advantage, and anything where the intellectual property in the fabrication method would leave with the part. Those are business judgements, not cost ones.
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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