Comparison of CNC Machining Materials

PEI (polyetherimide) is a high-performance thermoplastic engineering plastic that combines excellent heat resistance, mechanical properties, and chemical stability, enabling it to be widely used in high-end industrial fields such as aerospace, electronics and electrical engineering, and medical equipment.

Polypropylene (PP) is a well-balanced thermoplastic characterized by lightweight material, excellent chemical resistance, and good flexibility. Owing to these properties, it finds wide application in fields such as packaging, household appliances, automotive, daily necessities, and medical devices.

PET (polyethylene terephthalate) is a common thermoplastic polyester with excellent mechanical properties and strong chemical resistance. It also offers glass-like transparency and luster, with a high light transmittance of about 88–92%, and is widely used in beverage bottles, food packaging, and engineering plastics.

PC (polycarbonate, commonly known as bulletproof glue) is inherently pale yellow or colorless and transparent, featuring hardness, toughness and luster. It boasts prominent advantages: with a light transmittance of 90%, it not only has good mechanical strength but also excellent impact resistance, along with outstanding heat resistance and weatherability.

Acrylic (also known as polymethyl methacrylate, PMMA) boasts not only excellent optical performance but also outstanding UV resistance. With a light transmittance of up to 92%—comparable to glass—it has become a popular material in scenarios ranging from neon signs in shopping malls and display case panels in museums to precision optical lenses and stage light covers.

Nylon is a versatile and widely used material in CNC machining due to its exceptional properties. Its high tensile strength, low coefficient of friction, and resistance to wear and abrasion make it an excellent choice for applications requiring durability and reliability, such as gears, bushings, and bearings. Additionally, nylon’s low moisture absorption and good dimensional stability ensure consistent performance even in humid or varying temperature conditions.

Its ease of machining, coupled with its chemical resistance, also makes it suitable for applications in the automotive, aerospace, and medical industries. With its remarkable combination of properties, nylon stands out as a versatile and reliable material for a diverse range of CNC machining applications.

ABS (Acrylonitrile-Butadiene-Styrene Copolymer) is a well-balanced engineering plastic with good mechanical properties, excellent impact resistance, and easy processability. These characteristics have led to its widespread application in fields such as consumer electronics, household appliances, automotive industry, and daily necessities.

AISI 4140 Alloy Steel is a medium-carbon chromium-molybdenum steel with a carbon content of about 0.38–0.43%. It offers an excellent combination of strength, toughness, wear resistance, and machinability. When heat-treated, it provides outstanding mechanical properties, making it widely used in gears, crankshafts, connecting rods, bolts, and critical components in the oil and gas industry.

stainless steel 304 is also known as 18/8 stainless steel, which contains approximately 18% chromium (Cr) and 8% nickel (Ni). It not only possesses excellent oxidation resistance and corrosion resistance, but also has good workability and surface quality. Currently, it is the most widely used stainless steel grade in industrial manufacturing and civil applications.

Brass is an alloy primarily composed of copper and zinc. This golden-hued material not only exhibits excellent weather resistance and corrosion resistance, but its tensile strength also rivals that of low-carbon steel, demonstrating outstanding mechanical properties. Brass boasts exceptional machinability, enabling it to support higher feed rates during processing operations such as cutting and stamping, while requiring minimal cutting fluid. This combination significantly reduces both processing costs and process complexity.