PBI CNC Machining Services
Custom PBI Components Manufactured to Tight Tolerances for Semiconductor, Aerospace, Medical and Industrial Applications.
STEP / STP / IGS / X_T accepted · NDA available
Polybenzimidazole (PBI) is the highest-performance engineering thermoplastic available for CNC machining. With a continuous service temperature of 340°C — higher than PEEK — PBI is the go-to material for the most demanding applications in aerospace, semiconductor, and chemical processing.
PBI Material Properties
| Property | Value | vs PEEK |
|---|---|---|
| Max Service Temperature | 340°C (continuous) | +80°C vs PEEK |
| Glass Transition (Tg) | 427°C | +284°C vs PEEK |
| Tensile Strength | 160 MPa | +60% vs PEEK |
| Compressive Strength | 400 MPa | +100% vs PEEK |
| Hardness (Rockwell) | E79 | Excellent |
| Thermal Conductivity | 0.41 W/m·K | Higher than PEEK |
| Coefficient of Thermal Expansion | 23 µm/m·°C | Low |
| Flammability | UL 94 V-0 | Self-extinguishing |
PBI CNC Machining Capabilities
- Tolerances: +/-0.01mm achievable
- Processes: 5-axis milling, CNC turning, drilling, tapping
- Surface finish: Ra 0.8 µm as-machined
- Max part size: 600 x 400 x 300 mm
- Certifications: ISO 9001, full MTC traceability
PBI Machining Challenges & Solutions
PBI is extremely hard and abrasive, causing rapid tool wear. Our approach: diamond-coated carbide tools, optimized cutting parameters, and staged roughing/finishing passes to maintain tight tolerances while managing tool life. Coolant is required to prevent thermal degradation.
PBI Industry Applications
- Aerospace: Thermal insulators, engine seals, thrust washers
- Semiconductor: Wafer handling, test socket insulators, plasma chamber components
- Chemical: Pump wear rings, valve seats, seal faces
- Oil & Gas: High-temperature bushings, insulators, seals
PBI vs PEEK: When to Upgrade
If your PEEK parts are failing due to temperature, compressive load, or wear — PBI is the next step up. It offers approximately 60% higher tensile strength and can operate at temperatures where PEEK softens. The trade-off: PBI is more expensive and more challenging to machine. For most applications below 250°C, PEEK remains the more cost-effective choice.
PBI CNC Machining FAQ
How much does PBI CNC machining cost?
Explore our CNC machining capabilities for more details.
PBI is a premium material ($$$$$). Material cost is typically $500-800/kg. Machining costs are 1.5-2x that of PEEK due to tool wear. Request a quote for your specific part.
What is the lead time for PBI machined parts?
8-12 working days for standard parts. Expedited options available.
Can PBI be bonded or welded?
PBI does not melt and cannot be welded. Mechanical fastening or interference fits are the preferred joining methods.
Compare with PEEK CNC Machining or read our PBI machining guide.
Need PBI machined parts? Upload your drawing for a quote. ISO 9001 certified. Engineering support included.
PBI Machining Notes for Extreme-Temperature Components
PBI is used when standard high-performance plastics are no longer enough. Buyers usually consider PBI for high-temperature fixtures, wear components, semiconductor tooling, aerospace parts, and insulation parts that must keep mechanical strength where PEEK, PEI, or PPSU may soften. Because PBI material cost is high, the best results come from reviewing the design before material is cut.
Our machining review focuses on reducing tool wear, avoiding avoidable scrap, and protecting the features that matter most to the assembly. Deep pockets, very sharp internal corners, and long unsupported walls should be checked early. When possible, we recommend splitting critical dimensions into functional groups so inspection can focus on mating faces, bearing surfaces, slots, and high-temperature contact areas.
When PBI Is the Right Choice
- Use PBI when continuous heat, wear resistance, and compressive strength matter more than raw material cost.
- Use PEEK or PEI when the operating temperature is lower and cost efficiency is more important.
- For precision PBI parts, provide the STEP file, 2D drawing, tolerance callouts, and expected operating temperature.
- For prototype work, we can suggest geometry changes that reduce machining time while keeping the functional surfaces intact.
For related materials, compare PEI CNC machining, PEEK CNC machining, and our broader plastic material selection guide.