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How to compare three CNC machining quotes without guessing

September 12, 2026

You send one drawing, three shops answer and the numbers are 6.80, 9.40 and 11.20 per piece. The instinct is to take the first one. The useful move is to work out what the other two know that the first one does not.

Quotes differ honestly for reasons that have nothing to do with greed. This is how to line them up so you are comparing the same thing.

Normalise the scope before you compare anything

Ask each shop for the same breakdown:

Line	Why it matters
Piece price at your quantity	The number everyone quotes
Piece price at twice the quantity	Shows how much of the price is setup
Fixtures and programming	One-off, should not sit inside the piece price
First article and inspection	Often the difference between two quotes
Documents	Dimensional report, material certificate, certificate of origin
Packing	Export packing on a 250 piece order is not free
Freight basis	Which costs are already inside the number

Once the three quotes carry the same seven lines, most of the gap turns out to be scope, not price. In our experience the remaining difference is rarely more than 15 percent.

Read the lead time twice

A lead time is meaningless until you know when the clock starts. There are three common starting points:

1. From the purchase order. The shop takes material risk and the date is real.
2. From drawing approval. If the shop expects a signed drawing or a first article approval from you, your own response time is inside their quoted lead time.
3. From material arrival. Common on anything that is not stocked locally. Ask what the material lead time is, because that is the number that actually decides your date.

Two shops quoting “four weeks” can be three weeks apart in real delivery. Ask each one what has to happen before the clock starts.

The lines that hide money

Minimum order value. A low unit price with a 2,000 dollar minimum is not a low price on a 300 dollar order.

Price breaks. Ask for the next break point. If 250 pieces costs 9.40 and 500 costs 6.10, the setup is dominating and your real decision is about inventory, not machining.

Tooling ownership. If you pay for a fixture, say in writing that you own it. Otherwise a second source next year starts from zero.

Rework and rejects. What happens to an out-of-tolerance part: rework, replacement or credit, and who pays the freight on it. Settle this before the purchase order. After the inspection it is a negotiation and you have no leverage.

Payment terms. A first order to a new shop usually sits at 30 to 50 percent deposit with the balance before shipment. A shop asking for 100 percent up front on a large first order is asking you to carry all the risk.

When the cheapest quote is the expensive one

Look at the lowest number and ask what it implies:

• Did the shop read the tolerance? If your drawing calls for ±0.01 mm on a bore and the cheapest quote is 40 percent under the others, there is a good chance that line was not priced. You find out at first article.
• Is inspection in there? A shop with a CMM and a metrology room has that cost in its overhead. A shop measuring with calipers does not, and on a loose part that is fine. On a tight one it is the whole risk.
• Is the material the one you asked for? A substituted grade can be a sensible saving or a silent problem. Ask which grade is quoted and which certificate comes with it.
• Is the finish subcontracted, and to whom? Anodising is usually outsourced. A shop with a regular finisher gives you a date. A shop looking for one when your order lands gives you a delay.

The three questions that settle it

After the scope is normalised, three questions usually decide which shop you use.

“Have you made something like this before?” Ask for a part of similar size, tolerance and material. Not a customer name, which they should not give you, but the geometry and what was hard about it.

“What is the risk in this part from your side?” A shop that answers with a specific feature has programmed it in their head. A shop that says “no problem” has not.

“What would you change on the drawing to make it cheaper?” The best answer you can get is a real suggestion: a corner radius that matches a standard cutter, a tolerance that could open up, a face that does not need grinding. A shop that offers one is reading your part rather than filling in a form.

Then decide on total cost, not unit price

Add the one-off costs, divide by the order quantity and compare that number. Add freight if the basis differs. Then add the thing that does not sit in a spreadsheet: which shop answered your questions in a way that told you they understood the part.

On a first order with a new supplier that last point is worth more than the difference between 6.80 and 9.40.

If you are still at the start of this and your request has not gone out yet, the eight lines a shop needs will get you quotes that are comparable in the first place. When the drawing is ready, send it here and you get one quote from us, built on the same lines, with the parts made and inspected in Vietnam.

Questions we get on this

Keep reading

• What machining in Vietnam actually costs, and where the saving goes
• Minimum order quantity in machining, and why it is really a value