Materials Selection

Material Comparison Table

Material	Density (g/cm³)	Strength (MPa)	Machinability	Cost
Aluminum 6061-T6	2.70	310	Excellent	$
Aluminum 7075-T6	2.81	572	Good	$$
Stainless 304	8.00	585	Fair	$$
Stainless 17-4PH	7.78	1310	Fair	$$$
Carbon Steel 1018	7.87	440	Good	$
Titanium Ti-6Al-4V	4.43	950	Poor	$$$$
Inconel 718	8.19	1240	Very Poor	$$$$$
Delrin (POM)	1.42	70	Excellent	$
Nylon (PA66)	1.14	85	Good	$
PEEK	1.32	100	Good	$$$$$

How to Choose

• Lightweight → Aluminum 6061/7075 — best strength-to-weight for most applications
• Corrosion resistance → Stainless 304/316 — marine, food, medical
• High strength + corrosion → 17-4PH — aerospace structural fittings
• Heat + high strength → Titanium, Inconel — turbine, engine, chemical
• Wear/low friction → Delrin, Nylon — bushings, guides, rollers
• High temp + chemical → PEEK — semiconductor, medical, oil & gas

Cost Drivers

Material cost is one part of the equation. Exotic alloys (titanium, Inconel) also slow machining, increase tool wear, and raise labor cost. Where function allows, selecting a readily machinable aluminum or steel grade can cut total part cost dramatically.