PEEK Machining in Waco, TX: Unfilled, Glass-Filled, and Carbon-Filled Grades for Aerospace and Defense

Unfilled PEEK, produced from polyetheretherketone resin without reinforcing fiber or solid lubricant, provides the full benefit of the base polymer's thermal and chemical properties with the most predictable machining behavior of the three grades. Continuous-use temperature is 260 degrees Celsius in air; deflection temperature under 0.46 MPa load is 316 degrees Celsius. Tensile strength at room temperature is approximately 14,500 psi; flexural modulus is 550,000 psi. For defense electronics thermal management components, radome stand-offs, fluid handling components in contact with MIL-PRF-5606 hydraulic fluid, and EMI-transparent sensor windows, unfilled PEEK delivers the thermal and chemical performance without the abrasive carbide content of filled grades that accelerates tool wear. Machining unfilled PEEK requires sharp tooling and moderate speeds to avoid the two failure modes that characterize thermoplastic machining: melting and smearing from excessive heat, and stress cracking from aggressive clamping or interrupted cuts. Turning at 400 to 600 SFM with polished HSS or uncoated carbide, 0.003 to 0.006 inch per revolution feed, and light flood coolant or compressed air cooling maintains the material below its glass transition temperature of 143 degrees Celsius at the cutting zone. Dimensional stability of unfilled PEEK is excellent: linear thermal expansion coefficient is 2.6 times 10 to the negative 5 inch per inch per degree Fahrenheit, similar to aluminum, so thermal compensation in fixture design is manageable. Close-tolerance bores to plus or minus 0.001 inch are routinely achievable; bore dimensions should be measured at 68 degrees Fahrenheit and the print should specify the reference temperature. Unfilled PEEK rod and plate stock is available through plastics distributors in the DFW area with same-week delivery to Waco in diameters from 0.25 inch through 6 inch and plate from 0.25 inch through 4 inch thickness. Natural PEEK has a tan or brown color; buyers receiving clear or white PEEK should confirm they have not received a different polymer, as PEEK does not appear transparent or white in standard product form.

Thirty percent glass-filled PEEK increases flexural modulus to approximately 1,200,000 psi and reduces the coefficient of thermal expansion to 1.4 times 10 to the negative 5 inch per inch per degree Fahrenheit, making it the appropriate grade for structural brackets, stiffened frames, and load-bearing components where unfilled PEEK's compliance under sustained load is a design concern. The glass fiber reinforcement does not significantly change the continuous-use temperature or chemical resistance but does increase the abrasive wear on cutting tools: end mills and turning inserts see 30 to 50 percent shorter life compared to unfilled PEEK, and tool selection shifts toward TiN or TiAlN-coated carbide to manage edge wear. Thirty percent carbon-filled PEEK pushes stiffness to approximately 2,400,000 psi flexural modulus and adds electrical conductivity of 0.1 to 10 ohms per square, making it the correct choice for static-dissipative aerospace components, bearing surfaces, and structural members where both maximum stiffness and ESD protection are required simultaneously. The carbon fiber also provides lubrication at sliding interfaces, making carbon-filled PEEK self-lubricating without the off-gassing concerns that limit PTFE-filled grades in vacuum or elevated-temperature environments. For SpaceX-adjacent vacuum-exposed components or L3Harris defense electronics housings requiring ESD control, carbon-filled PEEK is the specification-of-record grade. Both filled grades require different surface finish expectations: the fiber pullout at the machined surface creates a texture that limits achievable Ra to 63 to 125 microinch under normal machining conditions, compared to 32 microinch achievable in unfilled PEEK. Where a smoother finish is required on a bearing bore in carbon-filled PEEK, diamond turning or bore honing achieves 32 microinch Ra at the cost of slower cycle time and higher tool expense. Buyers specifying filled PEEK should confirm whether the fiber content affects the dimensional tolerance on the application drawing, particularly in thin sections below 0.100 inch where fiber orientation from flow direction during rod or plate extrusion can cause slight anisotropic shrinkage.

PEEK for aerospace and defense applications is almost exclusively sourced as extruded rod, plate, or tube from Victrex or Solvay-branded resin, both of which maintain global production certification for aerospace-grade PEEK. Buyers should specify the resin brand and grade on the drawing when the application falls under an AS9100 or defense program, because not all PEEK stock on the market uses certified aerospace resin; commodity PEEK from unqualified sources may have lower crystallinity, inconsistent fiber content in filled grades, or undisclosed processing additives that affect dimensional stability. Receiving inspection should include a resin certification document traceable to the stock lot, available from qualified plastics distributors as a standard service. For ITAR-controlled programs at L3Harris or defense prime suppliers in Waco, PEEK machining shops need to hold ITAR registration to handle prints and EAR-controlled technical data. Most precision plastics machine shops in the DFW-Waco corridor that serve the defense sector carry ITAR registration; confirming this before sending prints avoids a compliance issue. Delivery lead times for machined PEEK components in production quantities of 10 to 100 pieces typically run 3 to 5 weeks from print issue to delivery, including material procurement, machining, and final inspection. For prototype quantities of 1 to 5 pieces from in-stock material, 1 to 2 weeks is achievable. ManufacturingBase supplier profiles include certification status and PEEK-specific machining capability flags so buyers can identify qualified Waco-area shops without a cold-call qualification process.