A Guide to PBI CNC Machining

Key Takeaways

• PBI offers the highest heat resistance of any plastic, along with exceptional strength and wear resistance.

• Its excellent chemical resistance, flame retardancy, and dimensional stability make it ideal for extreme industrial and semiconductor applications.

• PBI is a premium material with high cost and limited stock sizes, so careful material selection is essential.

Characteristics of PBI

PBI (polybenzimidazole) is a super engineering plastic with the highest heat resistance of any plastic material. It has a continuous use temperature of 345°C, a low coefficient of thermal expansion, and excellent dimensional stability under heat. Its combination of strength and heat resistance makes it a legitimate candidate as a metal replacement in demanding applications.

PBI also offers excellent wear resistance, making it well suited for sliding components in high-heat environments. It is flame retardant, rated V-0 under UL94, and has strong resistance to acids, alkalis, and organic solvents, along with good plasma resistance.

• Excellent mechanical strength and wear resistance

• Highest heat resistance of any plastic material

• Electrical insulation

• Excellent chemical resistance

• Flame retardant

• Good plasma resistance

Types of PBI

In addition to the standard grade, PBI is available in specialty grades with enhanced properties and low outgassing options.

• Standard grade

• Semiconductor process grade (low outgassing)

• Conductive grade

• Carbon-fiber-reinforced grade

Material Selection Notes

PBI is an expensive material, so it is important to carefully evaluate whether it is truly the right fit for a given application and avoid overspecifying. Standard stock sizes are limited, and some sizes are made to order, which means the size you need may not be available off the shelf or may require a longer lead time.

• High cost

• Limited standard stock sizes

A Guide to PBI CNC Machining

Yumoto Electric manufactures custom PBI machined parts starting from a single piece. We have experience with over 200 materials, including metals such as aluminum alloys, stainless steel, molybdenum, and titanium; and engineering plastics including PEEK, POM, and MC Nylon.

If you’re unsure about material selection or machining methods, we offer complimentary consultations to help optimize your design and production. For any questions, please feel free to contact us.