CNC Machining Service Pricelist

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  Key takeaways
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  What actually drives the price on a CNC machining service pricelist
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  How a quote is broken into line items
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  Tolerance and finish trade-offs that change the price
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  Material choice and how it lands on the quote
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  Quantity breaks, MOQ and how to read them
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  How to get a usable price in seven steps

A CNC machining service pricelist is not a menu with fixed prices. Every quote is a fresh calculation built from your geometry, your material callout, your tolerance block and your quantity. Two shops can quote the same STEP file and land 40% apart, and both can be honest. The difference usually sits in how they read the drawing, not in how much they want to earn.

Ask any supplier to show the quote broken out. A useful quote lists setup and programming hours, estimated cycle time per part, material cost with a stock size, any fixture or soft-jaw work, finishing cost, and inspection scope. If a quote is one number with no breakdown, you cannot tell whether a high price comes from a hard material or from a shop that simply does not want the job.

The setup line is a fixed cost. It does not shrink when you order five parts instead of one. That is why a single prototype bracket can cost more per piece than a 500-piece run of a more complex part: the program, the workholding and the first-article check get divided by a much larger number.

Cycle time is the variable you can influence. Wall thickness, pocket depth, internal corner radii and the number of setups all change how many minutes the spindle spends on the part. A drawing with R3 internal corners in a deep pocket forces a small tool, light passes and long run time. Open those radii to R6 and the same pocket machines in a fraction of the time.

Material and tolerance sit on top of that. A tight tolerance block on a part that does not need it is the single most common way buyers overpay. Mark only the features that matter. General dimensions can live at ±0.1 mm and cost far less.

Finishing and inspection are quoted last because they happen after machining. Anodizing is priced by batch surface area, plating by rack space, laser marking by setup plus character count. Inspection scales with how many dimensions you want recorded, not with how many parts you order.

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  Ask for a breakdownSetup, cycle time, material, finishing, inspection as separate lines.
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  Flag critical featuresTight tolerance only where the function demands it.
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  Send the real quantity1 pc, 50 pcs and 5,000 pcs are three different quotes.

Every shop works inside a tolerance band. GreatLight machines to ±0.005 mm (±0.0002 in) when a drawing calls for it. That number is not the default for every feature. It is the number used where a bore must fit a bearing or a mating face must seal.

Pushing a whole part to ±0.005 mm means slower feed rates, more in-process checks, temperature-stable finishing passes and sometimes a second operation on a jig borer. On a part with thirty dimensions, only three of them usually need that treatment. The other twenty-seven can hold ±0.1 mm with no extra cost at all.

Surface finish follows a similar rule. As-machined surfaces land around Ra 1.6–3.2 μm. A high-quality finish sits at Ra 0.8–1.6 μm and fine finishing reaches Ra 0.2–0.8 μm. Each step down means a different tool, a different stepover and more time on the machine.

Ask which surfaces touch a mating part, slide against a seal or carry an optical path. Those get the fine finish. Everything else is fine as machined. Anodizing and bead blasting also hide tool marks, so a cosmetic housing rarely needs a polished surface underneath a coating.

One warning: a tight tolerance on a thin wall is not the same problem as a tight tolerance on a solid block. Thin walls deflect under cutting force. If a wall is under 1 mm and the tolerance is ±0.01 mm, expect the shop to add support material, light passes and possibly a stress-relief step. That cost is real and should appear in the quote.

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  ±0.005 mmReserve for fits, bores and sealing faces.
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  Ra 0.8–1.6 μmTypical high-quality machined finish.
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  Thin walls under 1 mmExpect extra passes and support material.

Aluminium is the cheap end of the range. Grades like 6061, 6061-T6, 6082 and 7075 cut fast, produce clean chips and tolerate high spindle speeds. A shop can remove a lot of stock in a short time, so the cycle time line stays low. 7075 is tougher than 6061 and costs a little more in both stock and tool wear.

Stainless steels slow everything down. Grades 303, 304, 316 and 316L work-harden at the cut, so the tool must stay engaged and feed rates drop. 17-4PH in the hardened condition is slower still and often needs a specific insert grade. The material price per kilogram is higher, and so is the machine time.

Titanium and nickel alloys are the top of the range. Ti-6Al-4V and Inconel generate heat at the cutting edge, wear tools quickly and demand rigid setups and generous coolant. Cycle times can be three to five times those of aluminium on the same geometry. If your design allows an aluminium prototype for fit checks and a titanium final part, split the order that way.

Plastics are their own category. POM, PEEK, ABS and PC machine easily but move with temperature. PEEK is expensive per kilogram and abrasive on tooling. Carbon fibre is abrasive enough to require diamond-coated cutters. All of these appear in the material line of a quote, and the stock size you allow matters as much as the grade.

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  Aluminium 6061-T6Fast to cut, low cycle time, good for most housings.
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  Stainless 316LWork-hardens, slower feeds, higher tool cost.
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  Ti-6Al-4V and InconelHeat at the edge, short tool life, longest cycle time.

There is no minimum order quantity at GreatLight. A single prototype and a 10,000-piece run both go through the same quoting process. That does not mean the per-piece price is flat. It means you are not forced to buy a batch you do not need just to get a quote.

The quantity break curve has a distinct shape. The first few pieces carry the full setup cost. As quantity rises, setup spreads thin and the per-piece price drops fast. Then it flattens: once setup is negligible, material and cycle time set the floor, and doubling the order only shaves a small amount.

That shape tells you where to negotiate. If you are ordering 20 pieces and the quote feels high, ask what changes at 100. If the drop is large, the setup is the problem and a simpler fixture or one fewer operation may help. If the drop is small, the cost is in the material and the cycle time, and only a design change will move it.

Prototypes are a special case. Shops often machine prototypes on 3-axis machines with simple workholding, then switch to 5-axis or mill-turn for production. The prototype price reflects that manual approach. Do not use a one-off prototype price to estimate a 5,000-piece run, and do not assume a production price applies to a single part.

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  No MOQOne prototype or 10,000+ parts, same quoting path.
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  Setup spreadFirst pieces carry the program and fixture cost.
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  Flat tailPast a point, only material and cycle time remain.