Material Comparison Tool

Start with what your part needs to do. Pick aluminum when you need light weight, good corrosion resistance, and lower cost. Pick steel when you need high strength, wear resistance, or hardness. Aluminum machines faster and costs less per part. Steel is about 3 times stronger but takes longer to cut.

A machinability rating tells you how easy a material is to cut. A higher number means the material cuts faster with less tool wear. Easy-to-machine materials like 6061 aluminum and 303 stainless cost less to make. The CNC machine runs faster and tools last longer.

Use plastic when you need light weight, electrical insulation, or chemical resistance. Plastics like Delrin and PEEK machine fast and cost less per part. They work well for bushings, gears, insulators, and food-contact parts. Avoid plastic when you need high heat or heavy loads.

Yes. Harder metals like steel and titanium hold tight tolerances well. They do not flex during cutting. Soft metals like aluminum can flex slightly under tool pressure. Plastics expand with heat. They can be harder to hold below plus or minus 0.002 inches. Your CNC shop can adjust feeds and speeds to hit tighter tolerances on any material.

6061-T6 has a tensile strength of about 45 ksi and is the most common general-purpose aluminum. It welds well, anodizes easily, and costs less. 7075-T6 is a high-strength aerospace alloy with tensile strength around 83 ksi — nearly twice as strong. It is used for gears, shafts, and aerospace fittings where maximum strength-to-weight ratio matters. 7075 costs more, is harder to weld, and is more susceptible to stress corrosion. Choose 6061 for general parts and 7075 when you need the highest possible strength in aluminum.

Choose titanium when weight is critical and corrosion resistance must be excellent. Ti-6Al-4V has a tensile strength of 130 ksi but weighs only 0.160 lb/in³ — roughly half the density of stainless steel at 0.289 lb/in³. This makes titanium the best choice for aerospace structures, medical implants, and high-performance racing parts where every gram matters. Stainless steel is a better choice when cost is a constraint: titanium costs 3 to 5 times more per pound and takes significantly longer to machine due to its low machinability rating.

Machinability rating directly affects how long a CNC machine takes to cut your part and how fast cutting tools wear out. A material rated 10 out of 10 (like C360 brass) can be cut at maximum speed with minimal tool wear. A material rated 2 out of 10 (like Ti-6Al-4V titanium) requires slower feeds and speeds and dulls tools faster. In practical terms, a titanium part that would cost $100 in aluminum may cost $300 to $500 in titanium due to longer cycle times and higher tool consumption. Always factor machinability into your material budget.