CNC Material Selection Guide 2026: Strength, Cost, Machinability & Applications Compared

ByCNC Precision Tech

CNC Material Selection Guide 2026: Strength, Cost, Machinability & Applications Compared

Quick answer: For most prototype and general-purpose CNC parts, Aluminum 6061-T6 offers the best balance of strength, cost ($3–5/kg), and machinability. For high-strength requirements, Stainless Steel 304 or Titanium Ti-6Al-4V are preferred but cost 3–10x more per part. The table below compares 12 common CNC materials across the metrics that matter for machining.

12 CNC Materials: Head-to-Head Data Comparison

MaterialTensile Strength (MPa)Cost per kgMachinabilityCorrosion ResistanceDensity (g/cm³)Best For
Aluminum 6061-T6310$3–5★★★★★★★★☆☆2.70General purpose, prototypes
Aluminum 7075-T6572$5–8★★★★☆★★☆☆☆2.81Aerospace, high strength/weight
Stainless 304515$4–7★★★☆☆★★★★★8.00Food, medical, corrosion
Stainless 316580$6–10★★☆☆☆★★★★★8.00Marine, chemical, surgical
Carbon Steel 1045565$1–3★★★★☆★☆☆☆☆7.85Shafts, gears, structural
Alloy Steel 4140655$2–5★★★☆☆★☆☆☆☆7.85High-strength tooling, dies
Titanium Ti-6Al-4V950$30–50★☆☆☆☆★★★★★4.43Aerospace, medical implants
Brass C360350$6–10★★★★★★★★★☆8.50Fittings, valves, decorative
Copper C110220$8–12★★☆☆☆★★★★☆8.94Electrical, thermal components
Delrin / POM70$5–8★★★★★★★★★☆1.41Gears, bearings, insulators
PEEK100$80–120★★★☆☆★★★★★1.32High-temp, medical, aerospace
Nylon 6/680$3–6★★★★☆★★★☆☆1.14Wear parts, bushings
Data compiled from supplier specifications, MatWeb, and industry benchmarks Q1 2026. Machinability rated 1-5 stars. Prices are approximate bulk material costs; finished part cost depends on complexity and quantity.

Material Selection Decision Flow

  1. What is the operating environment? Wet/corrosive → stainless or titanium. Indoor/clean → aluminum or steel.
  2. What strength do you need? Under 300 MPa → aluminum or plastic. Over 500 MPa → steel or titanium.
  3. What is your budget per part? Under $20 → aluminum or steel. $20–100 → stainless or brass. Over $100 → titanium or PEEK.
  4. What is the weight limit? Density under 3 g/cm³ → aluminum, titanium, or plastics. No limit → steel or brass.
  5. Do you need certification? Medical → 316 SS or Ti-6Al-4V with material certs. Food → 304 SS. Aerospace → 7075 Al or Ti-6Al-4V with traceability.

Material Cost vs Part Cost: What Changes Between One Piece and Mass Production

MaterialRaw Material Cost (1 pc)Machining Cost (1 pc)Total (1 pc)Total (100 pcs, per part)Volume Discount
Al 6061 bracket$2$25$27$1063%
SS 304 shaft$5$35$40$1855%
Ti-6Al-4V mount$15$60$75$4540%
Delrin housing$3$20$23$865%
PEEK medical part$40$50$90$6528%
Estimated costs for a typical small-to-medium part. Actual pricing depends on geometry, tolerance, and supplier.

Common Material Selection Mistakes (And How to Avoid Them)

  • Mistake: Specifying 316 SS when 304 would work. Cost: 30–50% more in material + slower machining. Fix: Use 316 only when chloride exposure or surgical-grade corrosion resistance is required.
  • Mistake: Ordering PEEK for a part that could use Delrin. Cost: 10–20x higher material cost. Fix: PEEK is for >250°C or chemical resistance; Delrin handles most mechanical applications.
  • Mistake: Using 7075 aluminum where 6061 works. Cost: 40–60% more + harder to anodize. Fix: 7075 is for aerospace strength requirements; 6061 is fine for 90% of applications.
  • Mistake: Not considering material availability in the machine shop’s region. Fix: Confirm stock availability with your supplier before finalizing material choice, especially for titanium, PEEK, or specialty grades.

More Material Selection Guides

Get a Material Recommendation with Your Quote

CNC Precision Tech — China CNC machining sourcing and export support partner.

Material Choices by Industry

These application guides show how material choice connects with weight, corrosion resistance, insulation, thermal behavior, surface finish, and supplier route.