Benefits of Short Term CNC Processing

Short term CNC processing is subtractive machining of a small batch: one prototype, fifty brackets, or a few thousand parts. No mold, no die, no dedicated fixture that costs more than the parts. The program is written from your CAD model, the stock is cut from bar or plate, and the first article comes off the machine in days.

The boundary is not a fixed number. It sits where tooling cost per part stops dominating the price. A casting or injection mold spreads its cost across tens of thousands of pieces, so at low volume the tooling is the price. Below a few thousand parts, machining usually wins on total cost, and it wins on time by a wider margin.

We run these batches on 127 high-precision CNC machines, including 16 simultaneous 5-axis centers and 16 mill-turn centers. Maximum part size is 4,000 mm, so large frames and housings fit without splitting the part. There is no minimum order quantity: one piece or 10,000+ pieces use the same quoting path.

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  1 to 50 piecesPrototypes, fixtures, spares. Machining is the only practical route.
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  50 to 1,000 piecesBridge production and pilot builds. Fixture cost is small per part.
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  1,000 to 10,000 piecesCompare against die casting or molding; design stability decides.

The main benefit of short term CNC is compressed time. Once the model is frozen, there is no tool to design, cut, try out and rework. Programming and stock prep run in parallel, so production can start within 24 hours of a released drawing. Typical parts ship in 3-5 days.

Quotation and a free DFM analysis come back within 12 hours. That DFM pass matters more than the price line. It flags thin walls, deep pockets, tolerances tighter than the process holds, and features that need a second setup. Fixing those in the model costs nothing. Fixing them after the first batch costs a week.

Historical late-delivery probability on our jobs is below 2%. That number comes from scheduling that reserves machine time for short runs instead of pushing them behind long production orders. If a batch slips, you hear it from the engineer running the job, not from a tracking page.

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  12 hoursQuote plus DFM feedback on your files.
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  24 hoursProduction start after drawing release.
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  3-5 daysTypical shipment window for short runs.

Small batch does not mean loose work. We hold ±0.005 mm (±0.0002 in) on machined features, and surface finish runs from Ra 0.2-0.8 μm on fine finishes to Ra 1.6-3.2 μm as machined. The machine does not know how many parts are in the order.

What changes at low volume is inspection economics. We inspect 100% of parts before shipment regardless of quantity: raw material check, in-process monitoring, final inspection, with reports on request. On a five-piece run that means every part is measured. On a 5,000-piece run the same gates apply, with sampling plans where the drawing allows.

Repeatability across the batch comes from fixtures and probing, not from operator skill alone. For parts with true position or profile calls, we cut a first article, verify it against the model, and only then release the rest of the batch. If the first article is out, you get a call before the remaining stock is consumed.

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  ±0.005 mmAchievable tolerance on machined features.
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  Ra 0.2-0.8 μmFine finish for sealing faces and bearing seats.
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  100% inspectionEvery part checked before it ships.

Machining gives you alloy freedom that casting cannot match at this volume. Aluminum grades include 6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075 and ADC12. Stainless covers 303, 304, 316, 316L, 420, 430, 431, 440C and 17-4PH. Steel, copper alloys, titanium and engineering plastics are all cut from stock, not poured.

Finishing runs on the same short cycle. Anodizing in clear, color, hardcoat and conductive versions, electroless nickel, zinc, silver and gold plating, powder coating, black oxide, bead blasting, tumbling, brushing and polishing. Laser marking and engraving go down to 1.5 mm character height.

One caveat: some finishes have their own minimum batch economics, especially plating lines and hardcoat anodizing. Ask early. A finish that adds two days to a five-day job is worth knowing about before the order is placed, not after.

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  Aluminum6061-T6, 7075, 2024, 5083 and more from plate.
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  Stainless and steel303, 316L, 17-4PH, 4140, 4340, tool steel.
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  Titanium and specialsTi-6Al-4V, Inconel, magnesium AZ31B and AZ91D.

If the design is frozen and you need 50,000 identical parts, machining is the expensive route. Die casting or injection molding will beat it on unit cost, and the tooling spend is justified by volume. We will say so rather than quote a run that does not fit.

Some geometry cannot be cut. Hollow internal channels, undercuts that no tool reaches, and parts with molded-in texture are tooling jobs. Very large thin-wall parts can also deflect under cutting forces, so the achievable tolerance drops even if the machine envelope fits.

Cost per part falls as quantity rises, but not to zero. Programming, fixturing and first-article inspection are fixed costs on every order. Splitting a 200-piece job into four 50-piece releases multiplies those fixed costs four times. If the design is stable, release the full batch.

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  High volume, stable designTooling-based processes win on unit cost.
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  Internal channels and undercutsNot reachable by a rotating cutter.
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  Split releasesEach release repeats setup and inspection cost.