CadVex blog · 3 September 2026

What goes into a CNC machining quote? 7 cost drivers to check

Material, setups, cycle time, finishing, tolerances, quantity and margin. What drives the price of a machined part and what to check before you quote.

By CadVex · 6 min read

A machining quote is a stack of assumptions: stock size, number of setups, cycle time, outside processing, inspection, quantity and margin. When a job loses money, the cause is usually one of those assumptions, not the hourly rate itself.

Below are the seven drivers in roughly the order you build a price. For each one: why it costs money, what to check on the RFQ, and the mistake that tends to slip through.

1. Material and stock size

You pay for the blank, not the part. The starting stock is the finished envelope plus allowance for facing, the saw cut and workholding, rounded up to the next size your supplier sells or you keep on the rack. On a lathe, add grip length and part-off width. On a mill, leave enough material to clamp, or a tab if that is how the part will be held.

The ratio of what you buy to what ships is the buy-to-fly ratio. A high ratio costs you twice: once in material, and again in the machine time needed to turn the excess into chips.

What to check

• The next standard size up in every dimension, after allowances
• Whether that size is on hand, or means a full bar, a minimum cut charge or a minimum order
• Material certificates, if the customer requires them
• Scrap value on expensive alloys, if your shop recovers it

Common mistake: pricing material from the part's bounding box or finished weight. The customer pays for the bar you cut, plus the offcut you may never use.

2. Setups and programming

Programming, tool loading, fixturing and proving out the first part all happen before the first good part comes off the machine. Each additional setup (each re-clamp in a new orientation) adds fixturing, indicating, a first-piece check and another chance for error.

What to check

• How many orientations it takes to reach every feature
• Whether a 4th axis, a 5-axis machine or a mill-turn would remove setups, and at what machine rate
• Soft jaws or a dedicated fixture
• Whether it is a repeat job with a proven program. Programming drops; setup does not.

Common mistake: counting the obvious setups and missing the last flip for a single chamfer or counterbore on the back face.

Worked example: setup cost per part

The numbers below are illustrative round figures, not industry data. Say programming takes 2 hours and two setups take 1 hour each, at a shop rate of $100 per hour. That is $400 of one-off cost. Material and cycle time add $40 per part.

In this example, setup and programming are about 90% of the cost of a single part and under 10% at 100 parts. The variable cost is held constant to isolate the effect; in practice it often drops a little with quantity too.

This is why a prototype looks expensive next to a production price, and why each price break needs its own calculation rather than a discount off the single-part price.

3. Machining time

Cycle time multiplied by machine rate is often the largest variable cost on a machined part.

Roughing time depends mainly on the volume removed and how fast the material can be cut. Finishing time depends on surface area, surface-finish requirements and the smallest tool the geometry forces you to use. Then come the features: drilled, reamed and tapped holes, threads, grooves, slots and deep pockets.

What to check

• Volume removed from the actual blank, not an ideal one
• Machinability. Stainless steel, titanium and nickel alloys run much slower than aluminum.
• Smallest internal corner radius against pocket depth. Deep pockets with tight radii need long, small-diameter tools and gentle parameters.
• Thin walls and floors that need light passes
• Non-cutting time: tool changes, probing and rapids

Common mistake: estimating from removed volume alone. On a precise part with many small features, finishing and feature work can take longer than roughing. For the geometry that moves cycle time most, see the DFM checks that change part price.

4. Finishing and secondary operations

Anodizing, plating, passivation, heat treatment, painting and marking are often sent out. Outside processing brings vendor lot minimums, freight, masking and extra lead time. In-house, deburring, edge breaking and cleaning are labor that never shows up as a feature in the model.

Some processes change how the part is machined. Heat treatment can distort a part, so you may need to leave stock and finish afterwards, or cut hardened material at slower parameters. Anodizing adds a layer that changes dimensions, so threads, bores and fit faces may need masking or an allowance.

What to check

• Every note on the drawing: finish, coating, heat treatment, marking
• The vendor's minimum charge against your batch size
• Masking, racking and sequence: machine, treat, then finish?
• Lead time added by each outside process

Common mistake: using the vendor's piece price on a five-part batch and forgetting the lot minimum that will set the actual invoice.

5. Tolerances, surface finish and inspection

A tolerance tighter than your standard capability costs time: slower finishing passes, extra operations such as reaming, boring or grinding, in-process gauging and a higher scrap risk. A roughness requirement below your normal as-machined finish adds passes or a secondary process. Then the part has to be measured, and that time belongs in the quote.

What to check

• Which callouts are actually tighter than your shop standard. It is often a handful of features, not the whole part.
• GD&T controls such as position, flatness or profile that call for CMM programming and measuring time
• Documentation the customer expects: first-article report, certificate of conformance
• The sampling plan for production quantities

Common mistake: treating the whole part as tight tolerance, or the opposite: missing one tight bore buried in a note.

6. Quantity

Setup amortization is usually the biggest quantity effect, but not the only one. Repeat cycles get faster as the program and operator settle in. Larger material buys can lower the material price. Outside-processing minimums spread over more parts. A dedicated fixture may only pay for itself at volume.

What to check

• The price breaks the customer asked for, and the quantity they will realistically order
• The release schedule, and whether each release means a new setup

Common mistake: pricing a 500-piece blanket order on one setup when it will be called off in batches of 50. That can mean ten setups, not one.

7. Margin and commercial terms

Everything above is cost. The price adds markup and reflects the terms you are agreeing to.

Markup and margin are not the same number. A 25% markup on cost is a 20% margin on the selling price. Mixing them up quietly lowers your profit on every job.

What to check

• Lead time against current capacity. A rush job can mean overtime or bumping other work.
• Payment terms, packaging and shipping
• Quote validity, especially when material prices are moving
• Whether one-off costs such as fixtures are listed separately or spread over the parts
• Risk on a difficult or unproven part

Common mistake: applying one markup to every job regardless of risk, and hiding difficulty in the shop rate, where nobody sees it later.

How CadVex shows these drivers

CadVex starts from the STEP file and builds a draft estimate with the drivers shown separately: material and stock, setup and programming, machining, detail and finishing work, and markup. Stock can be matched against your own stock library, setups and programming are estimated from the geometry, and machining time covers both base material removal and features such as holes, pockets, slots and threads. DFM feedback flags deep pockets, small internal radii, thin walls and similar geometry before you commit to a price.

Every value can be reviewed and adjusted, and a question-mark icon next to applicable items shows the assumptions and calculation behind them. Shop rates and quantity are editable, so you can see how the unit price moves across price breaks. When the numbers match your judgment, CadVex generates the quote as a PDF on your own letterhead. It runs in the browser as CadVex Cloud or locally on Windows and Apple Silicon Macs as CadVex Desktop.

If you want to check it against your own numbers, try CadVex on one of your recent parts.