CNC Material Selection Guide

12 common engineering materials compared: machinability, strength, cost, corrosion resistance, and applications.

I've machined thousands of parts in 40+ different metals and plastics over 18 years. Material selection is where most project mistakes happen — picking the wrong grade costs far more than the material itself when you account for tool wear, cycle time, and scrap.

Here's what I tell every customer who asks "what material should I use?"

Engineering Alloy Matrix

MaterialMachinabilityTensile StrengthCorrosionCostBest Applications
6061-T6 AluminumExcellent310 MPaGood$Prototypes, structural, aerospace brackets, automotive
7075-T7351 AluminumGood570 MPaGood$$High-stress aerospace, missile components, gears
303 StainlessExcellent690 MPaGood$$Fittings, fasteners, shafts, connectors
304 StainlessGood760 MPaExcellent$$Food equipment, medical devices, enclosures
316 StainlessFair620 MPaExcellent$$$Marine, pharmaceutical, chemical equipment
17-4PH StainlessGood (annealed)1,100 MPaExcellent$$$Aerospace shafts, valve components, surgical tools
Ti 6Al-4V Grade 5Fair950 MPaExcellent$$$$Aerospace structural, medical implants, motorsport
Inconel 718Challenging1,350 MPaExcellent$$$$$Turbine blades, exhaust, oil & gas downhole
Brass C360Excellent400 MPaGood$$Fittings, valves, electrical components, decorative
Copper C110Good350 MPaGood$$$Electrical bus bars, heat sinks, welding tips
PEEKGood100 MPaExcellent$$$$Medical implants, aerospace, semiconductor, bearings
Acetal / DelrinExcellent70 MPaExcellent$$Bushings, gears, jigs, food-grade parts

See detailed guides: Aluminum · Stainless · Titanium · Inconel · PEEK

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