Machining
CNC Router vs CNC Mill
A CNC router is a gantry machine with a high-RPM, low-torque spindle built to sweep large sheet stock fast. A CNC mill is a rigid cast-iron machine that pushes high torque through hard metals to tight tolerance. The trade is work envelope and speed against rigidity and precision.
| CNC Router | CNC Mill | |
|---|---|---|
| Frame and rigidity | Aluminum or steel gantry, moving spindle | Cast iron column, 3,000 to 10,000 kg mass |
| Work envelope | 1,220 x 2,440 mm sheet beds common | 500 to 1,000 mm X travel on a typical VMC |
| Spindle | 18,000 to 24,000 RPM, 3 to 12 kW, low torque | 8,000 to 15,000 RPM, high torque at low RPM |
| Materials | Wood, plastics, foam, composites, aluminum sheet | Steel, stainless, titanium, plus everything softer |
| Achievable tolerance | +/-0.1 to 0.25 mm | +/-0.005 to 0.025 mm |
| Price | $5,000 hobby to $60,000 industrial | $60,000 to $250,000 for a VMC |
| Feed rate in sheet goods | 10,000 to 20,000 mm/min in MDF or ACM | 2,000 to 8,000 mm/min typical |
Choose CNC Router when
- Nesting full 1,220 x 2,440 mm sheets of wood, plastic, or ACM
- Parts that tolerate +/-0.1 mm or looser
- Aluminum panel and sign work at high feed rates
Choose CNC Mill when
- Steel, stainless, or titanium on the print
- Tolerances of +/-0.025 mm or tighter
- Heavy roughing, drilling, and rigid tapping cycles
The verdict
Buy the machine that matches your material, not your budget. A router earns its keep nesting sheet goods and aluminum panel at 10,000+ mm/min across a 4 by 8 ft bed. The moment the print says steel or shows +/-0.025 mm, only a mill's cast iron and torque will hold it.
Cost comparison
$25,000 to $60,000 buys a production-grade 4 by 8 ft router; a comparable VMC starts near $60,000 and passes $200,000 with a fourth axis and probing. Hourly rates follow: routers bill $40 to $75, mills $75 to $150. The crossover is material and tolerance, not volume. Cutting MDF on a mill wastes envelope and spindle speed; cutting steel on a router chews up $500 spindle bearings and scraps parts. Match the machine to the alloy first, then compare price.
Common questions
Can a CNC router cut steel at all?
A stout industrial router can take 0.2 to 0.5 mm passes in mild steel for one-off work, but chatter wrecks surface finish, tolerance drifts past +/-0.25 mm, and 24,000 RPM spindle bearings are not rated for the load. For any repeat steel work, use a mill.