What Drives the Cost of CNC Aluminum Parts

I talk to procurement managers every day who want to understand CNC aluminum pricing. The most common question I get: "Why do two similar-looking parts have such different quotes?"

The answer usually comes down to three factors: material choice, design complexity, and surface finish. Let me break each one down.

Material Selection

6061 aluminum is the workhorse. It machines beautifully, is widely available, and costs less than most alloys. But if your part needs higher strength — say for a structural aerospace bracket — 7075 or 2024 may be necessary. These alloys cost more per kilo and are harder on tooling.

I had a client specify 7075 for a simple mounting plate. After DFM review, we switched to 6061-T6, which had more than enough strength for the load. The part cost dropped nearly 30 percent.

Design Complexity and Tolerances

Every sharp internal corner, every deep pocket, every tolerance tighter than ±0.05 mm adds cycle time. Multi-axis work adds setup complexity. A flat plate with standard tolerances might take ten minutes. The same part with ±0.01 mm tolerances and compound-angle features might take an hour.

Our advice: apply tight tolerances only where the design actually needs them. Leave looser tolerances everywhere else. It saves money without affecting function.

Surface Treatment

Clear anodizing is common and relatively affordable. Hard anodizing, powder coating, or chemical conversion coatings add cost. If the part is internal and doesn't need corrosion protection or cosmetic appearance, skip the finish.

Getting a Fast and Accurate Quote

To get the best price from us, send STEP or IGES 3D files. Include your tolerance callouts, surface finish requirements, annual volume, and preferred surface treatment. We run DFM analysis on every quote — our engineers look at the model and identify cost-saving changes before pricing it.

Volume discounts kick in at 100 pieces and go up from there. Our proprietary quoting system returns real-time pricing on standard geometries.

Send your CAD files to chen@aoomtech.com for a quote within 24 hours.