Guides / Shops
The Jobs That Cost More Than They Pay
September 25, 2026 by The Alu CNC Parts editorial desk / how this is checked
Not every request is worth quoting, and the discipline to say so is what keeps a shop profitable. These are the patterns worth catching before you spend an hour on an estimate.
A model with no drawing, on a part that needs one
A STEP file carries geometry. It does not carry tolerance, alloy, temper, surface finish, thread callouts, coating or which features are critical.
For a simple bracket that is fine. For anything with a fit, a seal or a coating, quoting from the model alone means you are guessing at the expensive parts and the customer will hold you to whatever they had in mind.
Ask for the drawing. If there is not one, quote an estimate that is labelled as an estimate and lists what you assumed.
Tolerances applied to everything
A drawing with ±0.02 mm beside forty dimensions almost never means the customer needs forty features held to ±0.02 mm. It usually means somebody set a default in CAD and never revisited it.
This is not automatically a decline. It is a conversation, and often a profitable one, because you are the shop that told them the two or three features that actually matter and dropped their price. Quote it as drawn, then quote the alternative underneath.
The decline case is when you raise it and they insist on all forty without being able to say why. That job will have an inspection argument at the end of it.
Tolerances you cannot hold in production
There is a difference between making one part to ±0.01 mm and making two hundred. If the process is not capable, taking the job means sorting, rework and a customer who now distrusts everything you told them.
Say what you can hold, say what it costs, and let them decide. Shops that do this get called back with the work that suits them.
Flatness with no free state note
“Flat within 0.05” on a large plate, with nothing about the free state, is an argument waiting to happen. You can hold it in the fixture and the customer can measure it unclamped on a surface plate, and you will both be right.
This is a clarification, not a decline, and the answer changes your whole process route. If it is free state on a big plate, you are pricing rough, rest and finish and the right material, not a single operation.
Coating specified without the detail that decides it
“Black anodize” is not a specification. Type II covers 5 to 25 um, and the growth into the fits differs across that range by more than most tolerances allow.
What you need before quoting: type, class, thickness, colour, and which features are masked. Without masking instructions on a part with tapped holes and a bore, somebody is going to be disappointed and it will be treated as your problem.
Volume promises doing the pricing
“Quote 10 now but we will need 5000 next year” is sometimes true. Price the 10. If they want the 5000 price, quote both and make the volume commitment explicit in writing.
Shops that discount the prototype against a forecast order that never arrives are subsidising a customer’s development programme.
No decision maker in the conversation
A request routed through someone who cannot answer a question about the part, and cannot get an answer, is a job where every clarification takes a week. On a tight lead time that alone can make it unprofitable.
The signals that point the other way
Requests worth prioritising look like this: the drawing has a general tolerance note and three called out features. The alloy and temper are both stated. The finish names a type, a thickness and what is masked. There is a quantity and a date. And when you ask a question, you get a real answer within a day.
That customer has bought machined parts before. They are usually worth more over five years than the cheapest job on your list this month, and they are the reason it is worth being the shop that reads the drawing properly.
Sources
Figures in this guide are checked against the following. Published values are typical ranges for test material, not a guarantee for your part.
Frequently asked questions
Is it bad for my reputation to decline work?
The opposite, when you decline with a reason. A shop that says 'we cannot hold 0.01 mm on that bore in production, we can hold 0.025 mm, here is what that costs' is more valuable to a buyer than one that takes the job and misses. The decline is what makes the next yes credible.
What if the customer will not send a drawing?
Quote an estimate clearly labelled as one, based on stated assumptions, and say a firm price follows a drawing. Never issue a firm number from a model alone on a part with tolerance or finish requirements, because the drawing is where all of that lives.
How do I tell quote shopping from real buying?
Ask about quantity, timing and what happens after the first order. A real buyer has answers. Someone collecting numbers to benchmark an existing supplier usually will not, and will not want to talk through the part either.
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