Polyether ether ketone tubing is one of the most capable thermoplastic tube products available for demanding industrial, medical, aerospace, and semiconductor environments. Kaxite Sealing manufactures and supplies PEEK tubes in a broad range of diameters, wall thicknesses, lengths, colors, and performance grades. Every production lot is backed by full material traceability, dimensional inspection data, and optional certificates of conformance. Unlike metal tubing, PEEK tubes combine corrosion resistance, light weight, electrical insulation, and high-temperature stability in a single product, which reduces component count and long-term maintenance costs.
Kaxite Sealing works with raw PEEK resin from internationally recognized polymer producers. The material is processed under tightly controlled extrusion and compression molding conditions to achieve consistent inner and outer diameters, low ovality, and smooth internal surfaces. Standard stock sizes and custom-manufactured dimensions are available with quick turnaround. This product focus allows engineers to source prototype quantities and production volumes from a single supplier without changing material specifications.
PEEK belongs to the polyaryletherketone family. Its semi-crystalline structure delivers a unique balance of mechanical strength, thermal stability, and chemical inertness. The most important advantages for tube applications include:
Kaxite Sealing offers PEEK tubes in a wide array of standard and custom sizes. The table below summarizes the standard dimensional capabilities. Tolerances are influenced by tube diameter and wall thickness, but the values shown represent typical production capability for extruded and machined tubes.
| Parameter | Standard Range | Typical Tolerance |
|---|---|---|
| Outer diameter | 2 mm to 200 mm | ±0.05 mm to ±0.15 mm depending on diameter |
| Inner diameter | 0.5 mm to 180 mm | ±0.05 mm to ±0.10 mm for small bores |
| Wall thickness | 0.25 mm to 25 mm | ±0.05 mm for thin walls, ±0.15 mm for heavy walls |
| Length | 1,000 mm, 2,000 mm, 3,000 mm standard | +5 mm / -0 mm on standard cut lengths |
| Ovality | Controlled by mandrel extrusion | Typically less than 0.10 mm for diameters up to 50 mm |
| Straightness | 0.5 mm per 300 mm for most sizes | Improved straightness available on request |
Custom cut-to-length pieces, tight-tolerance machining, chamfering, notching, and surface finishing are available. Engineers can specify exact inner and outer diameters, and Kaxite Sealing can produce non-standard wall ratios for specialized flow, insulation, or load-bearing requirements.
PEEK tubes are not limited to a single formulation. Different filler systems modify stiffness, wear resistance, thermal conductivity, and electrical behavior. The most common grades stocked and supplied by Kaxite Sealing are listed below.
| Grade | Key Characteristics | Common Applications |
|---|---|---|
| Unfilled PEEK | High elongation, excellent chemical resistance, natural beige color, good electrical insulation | Medical components, seals, insulators, fluid handling |
| 30% Glass Fiber Filled PEEK | Higher stiffness and creep resistance, improved dimensional stability at elevated temperature | Structural spacers, pump wear rings, electrical connectors |
| 30% Carbon Fiber Filled PEEK | Highest stiffness and load capacity, lower friction, improved thermal conductivity, black color | Bearings, bushings, compressor components, high-load wear parts |
| Bearing Grade PEEK | Contains carbon fiber, graphite, and PTFE for reduced friction and improved wear life | Dry-running bushings, sliding elements, wear pads |
| Medical Grade PEEK | Validated for biocompatibility, implantable or short-term tissue contact, traceable resin | Surgical instruments, endoscopic components, dental abutments |
| Electrically Conductive PEEK | Carbon-based formulation with controlled surface resistivity | Semiconductor handling, static dissipation, sensor housings |
All grades can be supplied as extruded tubes or compression-molded tubes. Extrusion is preferred for long lengths and thinner walls, while compression molding is better for very thick walls, large diameters, or special filler loadings.
The mechanical performance of PEEK tubes depends on the selected grade. The table below provides representative values for dry-as-molded material at 23°C. Actual values may vary slightly depending on tube size and processing method.
| Property | Unfilled PEEK | 30% Glass Filled PEEK | 30% Carbon Filled PEEK |
|---|---|---|---|
| Tensile strength | 95-100 MPa | 150-170 MPa | 200-230 MPa |
| Tensile modulus | 3.6 GPa | 9-10 GPa | 13-15 GPa |
| Flexural strength | 160-170 MPa | 230-260 MPa | 300-340 MPa |
| Flexural modulus | 4.0 GPa | 9.5 GPa | 13 GPa |
| Elongation at break | 20-30% | 2-3% | 1.5-2% |
| Compressive strength | 120-130 MPa | 180-200 MPa | 220-250 MPa |
| Hardness, Rockwell M | 99-100 | 102-105 | 105-108 |
These mechanical values help designers compare PEEK tubes with metals such as stainless steel, aluminum, and titanium. PEEK offers roughly one-fifth the weight of steel and a much lower coefficient of thermal expansion than most unfilled thermoplastics.
PEEK tubes are frequently chosen for high-temperature electrical insulation and thermal management applications. The following data are useful when selecting a tube for continuous service or intermittent thermal cycling.
| Property | Typical Value |
|---|---|
| Melting point | 343°C |
| Glass transition temperature | 143°C |
| Continuous service temperature | -60°C to 260°C |
| Short-term maximum temperature | 300°C |
| Thermal conductivity, unfilled | 0.25 W/m·K |
| Thermal conductivity, carbon filled | 0.90-1.00 W/m·K |
| Coefficient of linear thermal expansion | 45-55 × 10-6 m/m·K below Tg |
| Dielectric strength | 19-20 kV/mm for 1 mm thick wall |
| Volume resistivity, unfilled | 1015 - 1016 ohm·cm |
| Flammability rating | UL 94 V-0 |
PEEK tubes can operate continuously in hot water, steam, and many thermal fluids without significant hydrolysis. This performance is important in medical autoclave cycles, semiconductor wet benches, and oil and gas downhole tools where repeated temperature spikes occur.
PEEK tubes resist a wide range of chemicals. The material is attacked only by a few highly oxidizing acids at elevated temperatures. Important compatibility notes include:
Because PEEK tubes do not corrode electrochemically, they are often used to replace stainless steel or titanium tubing in aggressive chemical feed lines, analyzer sample lines, and acid dosing systems. The low extractable profile also makes PEEK suitable for high-purity water and pharmaceutical process streams.
Kaxite Sealing supplies PEEK tubes to manufacturers and maintenance teams across many industries. Typical applications are grouped below.
Kaxite Sealing produces PEEK tubes through precision extrusion and compression molding. The manufacturing method is selected based on diameter, wall thickness, length, and filler system. For demanding applications, extensive post-processing is available.
Custom PEEK tubes can be produced with inner diameters as small as 0.5 mm for capillary applications and as large as 180 mm for structural sleeves. Wall thickness can be adjusted to handle pressure, vacuum, or mechanical loading. Kaxite Sealing engineers can assist with material selection and design review before production.
Every PEEK tube order from Kaxite Sealing is controlled through a documented quality system. Standard quality documentation includes a material certificate, a dimensional inspection report, and lot traceability back to raw resin batch. Additional certifications available on request include:
Dimensional inspection is performed with calibrated micrometers, bore gauges, and optical measuring systems. For critical applications, 100% inspection can be specified instead of batch sampling. Kaxite Sealing also offers first article inspection reports and PPAP-style documentation for automotive and aerospace customers.
What is the maximum continuous operating temperature for PEEK tubes?
PEEK tubes can be used continuously at temperatures up to 260°C. At 150°C, unfilled PEEK retains more than 50% of its room-temperature tensile strength. Short-term excursions up to 300°C are possible for limited periods, but load, chemical environment, and thermal cycling should be evaluated. Carbon fiber filled grades generally provide better creep resistance at elevated temperature than unfilled PEEK.
Are PEEK tubes available in FDA-compliant or medical grades?
Yes. Kaxite Sealing supplies unfilled medical grade PEEK tubes that meet USP Class VI requirements and can be supported with ISO 10993 test data. These grades are manufactured from traceable resin and are suitable for short-term tissue contact, surgical instruments, and diagnostic equipment. Food contact grades are also available for processing machinery. It is important to specify medical or food grade at the time of inquiry because not all stock tubes are produced from those formulations.
Can PEEK tubes be mechanically machined without cracking or losing strength?
PEEK tubes machine well using standard metalworking equipment with sharp carbide or diamond tooling. Low cutting speeds and adequate cooling prevent heat buildup and surface microcracking. After heavy machining, a stress-relief annealing cycle may be recommended to reduce internal stresses. Kaxite Sealing performs CNC machining, drilling, threading, and grooving in-house to avoid introducing defects.
What is the difference between unfilled PEEK and carbon-filled PEEK tubes?
Unfilled PEEK tubes offer higher elongation, better electrical insulation, natural beige color, and excellent chemical resistance. Carbon-filled PEEK tubes provide roughly three times the stiffness, higher load capacity, improved thermal conductivity, and lower thermal expansion. The trade-off is reduced ductility and black color. Carbon-filled PEEK is preferred for bearings, high-load wear parts, and applications requiring dimensional stability under mechanical stress.
Can PEEK tubes handle high internal pressure?
Pressure rating depends on tube diameter, wall thickness, temperature, and safety factor. Thin-walled PEEK tubes are generally used for low-pressure fluid transfer or as protective sleeves, while thick-walled tubes can handle significantly higher pressure. For a precise pressure rating, calculations should include hoop stress, long-term creep, and temperature derating. Kaxite Sealing can recommend a wall thickness based on service conditions when provided with pressure, temperature, and media details.
Are PEEK tubes resistant to steam and autoclave sterilization?
Yes. PEEK tubes withstand repeated steam autoclave cycles at 121°C to 134°C without significant loss of mechanical properties. Hydrolysis resistance is one of the primary reasons PEEK is selected for reusable medical devices and pharmaceutical process components. After hundreds of autoclave cycles, the material maintains dimensional stability and surface hardness better than most other high-temperature thermoplastics.
What standard colors are available for PEEK tubes?
The natural color of unfilled PEEK is light tan or beige. Carbon-filled PEEK is black. Glass-filled PEEK is typically brownish-black. Custom colors can be produced for specific branding or identification requirements, although additive systems may slightly affect mechanical or compliance properties. For FDA and medical applications, natural unfilled PEEK is most commonly used.
Does Kaxite Sealing provide material certificates with PEEK tube orders?
Yes. Every order can be supplied with a material certificate identifying the resin manufacturer, grade, lot number, and date of processing. Dimensional inspection reports, RoHS and REACH declarations, and other quality documents are available. For medical and aerospace customers, full lot traceability from raw resin to finished tube is maintained and archived.
Can PEEK tubes be bonded or joined to other materials?
PEEK has a low surface energy, so bonding requires proper surface preparation. The most common methods include plasma treatment, corona treatment, or chemical etching followed by epoxy, cyanoacrylate, or polyurethane adhesives. Mechanical fastening, press fitting, and threaded connections are also widely used. Kaxite Sealing can prepare tube ends and surfaces for secondary bonding operations.
Are thin-walled PEEK tubes available for capillary or insulation applications?
Yes. Kaxite Sealing can produce thin-walled PEEK tubes with wall thicknesses down to 0.25 mm and inner diameters as small as 0.5 mm. These products are used as capillary tubing, electrical insulation sleeves, and protective covers. Thin-walled extrusions are carefully controlled for ovality and surface quality. Custom cutting and end finishing are available even for small diameters.
