Guides / Choosing a Supplier

Picking a Shop That Will Actually Make Your Part Well

September 24, 2026

There is no best machine shop. There are shops that are a good fit for your part and shops that are not, and the difference has more to do with machine size, materials and the quantities they like than with anything on a website.

Here is how to work out which is which before you commit.

Know which kind of shop you are talking to

Type	What it is set up for	Where it hurts
Job shop	Mixed work, small to medium batches, changes setups constantly	Lead time when it is busy
Production shop	Hundreds or thousands of the same part, tight cycle times	One off work is an interruption and gets priced that way
Prototype shop	Fast turnaround, one to ten pieces, used to incomplete drawings	Price per part if you later need a hundred
Race or fab shop	Automotive context, welding and fabrication under the same roof	Tight tolerance work and inspection paperwork
Marketplace	Instant price, wide capacity, routed to whoever is free	Nobody owns your part, and questions get slow answers

A one off swap bracket belongs at a prototype shop or a job shop. Two hundred repeat parts belong at a production shop. Sending each one to the other kind is the most common way people get a price that makes no sense.

Seven questions worth asking

Send these with your drawing, or ask them on the phone. The answers tell you more than any gallery of shiny parts.

1. What machines would this part run on, and what is the working envelope? You are checking that your part fits with clamping room to spare.
2. What materials do you cut every week? A shop that runs aluminum daily and steel occasionally will quote your steel part carefully and slowly.
3. Do you program in house? If CAM is subcontracted, revisions get slower and more expensive.
4. Who does the anodizing or plating, and is it in your quote? Finishing arranged by the shop is almost always cheaper and faster than you arranging it.
5. How do you inspect, and what do I get with the parts? A caliper check is normal on a bracket. If you need a report with numbers on it, say so now.
6. What is the lead time counted from? Order date and approved drawing date can be two weeks apart.
7. Will you tell me if something on my drawing is going to cost me money? The answer to this one separates suppliers from vendors.

Answers that should worry you

• “We can make anything.” No shop can. A useful answer names a limit.
• A quote by return email with no questions, on a drawing that has a question in it. Someone either did not read it or has priced the risk in silently.
• Refusing to say what machines are in the building. Shops that own their machines are usually happy to talk about them.
• Agreeing to every tolerance without comment. If you asked for plus or minus 0.01 mm on a 300 mm feature and nobody pushed back, nobody read it.
• A price far below everything else. Ask what tolerance and finish it is based on before you celebrate.
• No address, no name, no way to reach a person. You are going to send this shop a file and money.

What to do on the first job

Start smaller than you want to. A shop that makes one part well earns the batch. A shop that gets a hundred parts wrong on the first order costs you the project.

Then:

• Ask for a photograph of the first part before the rest are run, on any batch over about ten pieces
• Ask for the critical dimensions to be measured and reported on the first article
• Keep the whole job in one place if you can. Splitting machining and finishing between two suppliers means nobody owns the result
• Keep the drawing revision number on every message. Most disputes come from two versions of the same file

Judging the quote itself

Compare quotes on what they include, not on the total. A quote that looks expensive is often the only one that includes finishing, inspection and the fixture that the part actually needs.

Look for the things that are missing: finishing, deburring, material certification, freight, and what happens if the first article is wrong. A shop that writes those lines down has thought about the job. For what sits inside a price, see what a custom CNC auto part costs, and for the drawing that gets you a firm number, what to send a machine shop.

What we do here

We read your RFQ and pass it to shops that fit the part, up to three of them. Fit means the machine envelope, the material and the quantity match what the shop actually runs, not that the shop says yes to everything. They quote you directly, you choose, and the order never comes through us.

Send your part and we will do the filtering. Or start at the buyer’s guide if you are still deciding how the part should be made.

See also: IATF 16949 explained, for when a buyer asks whether a shop needs the automotive quality certificate.

Frequently asked questions

Keep reading

• Where Aftermarket Car Parts Buyers Meet Suppliers in 2027 and 2028
• Billet Differential Cover Machining: What to Specify for Rear End Parts