Primary process: CNC Milling. The full route, materials, tolerances and design tips for a prototype, with an indicative cost.
CNC MillingPrimary process
MachiningFamily
8Route steps
+/-0.025mmTypical tol.
A prototype is primarily made by CNC Milling. CNC milling removes material from a fixed blank with a rotating cutter moving on several axes, carving complex features to tight tolerance. Below is the full route to make a prototype, the materials it suits, the tolerances to expect and the main design points. The route is free, from the finder.
Step by step
How a prototype is made
The usual route, raw material to finished part. The amber step is where the prototype gets its basic shape.
Stock
Start from bar, plate or billet sized for the prototype.
CNC Milling (roughing)
Rough out the main shape, leaving stock on the critical surfaces.
Tooling None Tolerance ±0.125mm, to ±0.025mm Lead 1 to 10 days
Finish machining
Take the finishing passes that bring the prototype to tolerance.
Tooling None Tolerance ±0.125mm, to ±0.025mm Lead 1 to 10 days
Holes and features
Drill, ream and tap, and where needed broach splines or cut gear teeth.
Tooling None Tolerance ±0.05 to 0.2mm Lead hours to days
Heat treatment
Harden and temper if the prototype must resist wear or load, then finish-grind.
Tooling n/a Tolerance can distort Lead days
Grinding
Where the prototype has bearing or sealing surfaces, grind them to the tightest tolerance and finish.
Tooling Low (wheel) Tolerance ±0.002 to 0.02mm Lead days
Surface finish
Anodise, plate or coat for wear and corrosion resistance.
Tooling Low Tolerance adds microns Lead days
Inspection
Measure the prototype against the drawing, on a CMM for close work.
Need the real cost for a prototype? The free route above is yours. Unlock the full dossier to quote and source it.
Where this process typically lands. Tighter is possible with extra operations like grinding, at higher cost.
Materials
Materials for a prototype
Grade
Why it suits this
Aluminium 6061/7075
Fast to cut, strong
Steel 1045/4140
Strong
Stainless 304/316
Corrosion, slower cut
Design
Design tips
General pointers. The full design-for-manufacturing list for a prototype is in the dossier.
Deep pockets / thin walls.Limit depth-to-width, add radii.
Sharp internal corners.Add tool-radius corners.
Cost
What a prototype should cost
Prismatic parts; priced by machine time and setups. Fewer setups and looser tolerance drop the price fast.
PER-PART COST vs VOLUME
Per-part cost drops as volume spreads tooling and setup over more parts. The exact figures for a prototype at your volume, in your currency, are in the dossier.
MODEL EST.
$57 to 160per part at 1 off
A rough ballpark only. The dossier gives should-cost at your exact volume and currency, with the full breakdown.
GET THE FULL DOSSIER
Everything you need to quote and source it
The free route above is yours. To actually put a number on a prototype and buy it well:
Should-cost at your exact volume in 12 currencies, with the material, processing, tooling and overhead breakdown
Who to source from, typical MOQ and lead time, and the exact RFQ checklist to send
A quote checker that tells you if a supplier quote is fair, and the red flags to watch
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A prototype is primarily made by cnc milling. The route is: Stock; CNC Milling (roughing); Finish machining; Holes and features; Heat treatment; Grinding; Surface finish; Inspection.
What does a prototype cost?
It depends on size, tolerance and volume. As a rough ballpark it starts around $57 to 160 per part at 1 off and falls with quantity. The dossier gives should-cost at your exact volume and currency. A model estimate, not a quote.
What material is a prototype made from?
Common choices are Aluminium 6061/7075; Steel 1045/4140; Stainless 304/316.
What is the main process for a prototype?
CNC Milling. Precision prototypes and low to medium-volume parts of almost any shape and material.
See the exact route and should-cost for your part
The free finder maps your part to its process and full route. Pro adds should-cost at your volume, sourcing and an RFQ draft.
