CNC Machining
Materials

There's no single "best" material - it depends on your specific requirements. Aluminum 6061 offers the best balance of machinability, cost, and performance for general applications. For high strength, consider 7075 aluminum or 4140 steel. For corrosion resistance, stainless steel 304/316 is ideal. For precision and chemical resistance, engineering plastics like POM or PEEK excel.

Choose aluminum when you need lightweight parts, excellent machinability, and good corrosion resistance at lower cost. It's ideal for aerospace, electronics, and general manufacturing. Choose stainless steel when you need superior corrosion resistance, higher strength, food-grade compatibility, or parts that will be exposed to harsh chemicals or marine environments. Stainless costs more but offers better durability in demanding applications.

Yes, but with limitations. Engineering plastics like POM (Delrin) and PEEK can achieve tolerances of ±0.05mm to ±0.1mm, depending on part geometry and size. However, they're generally not as dimensionally stable as metals due to thermal expansion and moisture absorption. For critical dimensions, consider material stability, machining temperature control, and post-machining dimensional verification.

For prototypes, prioritize machinability and cost-effectiveness - aluminum 6061, brass, or POM are excellent choices for testing fit, form, and basic function. For production parts, match the material to end-use requirements: environmental conditions, mechanical loads, regulatory requirements, and cost targets. Sometimes prototype and production materials differ, but ensure functional testing validates the final material choice.

Material compatibility varies: Aluminum works with anodizing, powder coating, and plating. Stainless steel is compatible with passivation, electropolishing, and PVD coatings. Carbon steel accepts zinc plating, black oxide, and paint systems. Plastics are limited to mechanical finishes like polishing and texturing, plus some specialized coatings. Always verify finish compatibility with your material grade and part geometry before finalizing specifications.

Material costs vary significantly: Carbon steel and aluminum 6061 are most economical. Stainless steel costs 2-3x more than aluminum. Specialty alloys like 7075 aluminum or 17-4PH stainless are 3-5x standard material costs. Engineering plastics range from moderate (POM, Nylon) to expensive (PEEK can be 10-15x the cost of aluminum). Consider both material cost and machining time - easier-to-machine materials can offset higher material costs through reduced labor.