01 / CFRP
Automation & robotics
Moving links, lightweight supports and end-effector members where lower moving mass matters.
Send acceleration, reach, payload and joint details.
F1-FORM· Carbon fiber tubes
Pultruded carbon fiber tubes
Longitudinal stiffness. Less moving mass. Develop CFRP tubing around your component’s dimensions, loads and connections, with F1 review of the laminate, tooling and finished-part requirements.
FIG. 1 Fibers follow the tube axisConcept diagram
Put stiffness in the direction of the load
A constant cross-section and continuous longitudinal reinforcement make pultrusion a useful route for straight, repeatable components. Start with the load path and allowable deflection.
Carbon reinforcement can make a compact, lightweight member attractive when movement, reach or alignment drives the design. The finished tube’s bending stiffness depends on both its longitudinal modulus and section geometry; fiber grade alone cannot establish component performance.
During pultrusion, continuous reinforcement is impregnated with resin, formed and cured through a heated die, then pulled and cut. The fiber arrangement, cure and dimensional controls must be defined together. Explore the pultrusion process.
For general structural tubing, compare our fiberglass round tubes and fiberglass square and rectangular tubes alongside the carbon option.
Define the tube you need
Custom dimensions and processing are reviewed against your drawing. Tooling availability, achievable tolerances, sample timing and production quantity are confirmed in the quotation.
- Cross-section
- Round hollow tubing; submit square, rectangular or other constant sections for tooling review.
- Diameter & wall
- Specify outside diameter, inside diameter and nominal wall in mm or inches. Identify the dimensions that control fit.
- Length & quantity
- Finished length and piece count per item, plus trial quantity and expected repeat demand.
- Dimensional controls
- Agree OD / ID tolerances, wall variation, ovality, straightness and end squareness on the drawing.
- Fiber & resin
- Define carbon grade, reinforcement architecture and resin against stiffness, exposure and temperature requirements.
- Surface & fabrication
- State bonding zones, surface finish, coating, end preparation, holes and fitting requirements for review.
- Acceptance evidence
- Agree inspection method, sampling, material identification and any mechanical or assembly tests before ordering.
Geometry check
For a uniform round section, ID = OD − 2 × wall. A nominal calculation does not establish bore fit; include the mating part and required clearance.
Performance evidence
Request data for the proposed tube laminate, test direction and conditioning. Numerical strength, modulus, temperature and tolerance guarantees belong in the agreed specification.
Carbon fiber or fiberglass tubing?
Compare both materials against the same load case, deflection limit, environment and finished assembly. Neither material name by itself defines the right tube.
| Decision | Carbon fiber tubes · CFRP | Fiberglass tubes · GFRP |
|---|---|---|
| Selection priority | Low moving mass and high longitudinal stiffness. | A balance of structural performance and material cost. |
| Electrical behavior | Carbon reinforcement conducts electricity; do not specify as electrical insulation. | Glass reinforcement suits insulating designs; qualify the resin, part and assembly for the duty. |
| Load direction | Predominantly axial reinforcement; assess torque, local crushing and joints separately. | Roving, mat and fabric content also govern directional properties and connection behavior. |
| Environment & interfaces | Review resin exposure and isolate carbon from susceptible metals where moisture is present. | Review resin, weathering and connection materials for the exposure. |
| Commercial decision | Justify the material premium through mass, deflection or equipment performance. | Often the starting point for cost-led frames, rails and general structural members. |
Where a lighter, stiffer member can help
These are application starting points. Suitability depends on the tube, connections and validation of the complete assembly.
02 / CFRP
Instrumentation
Sensor supports and positioning structures where deflection and dimensional stability guide material selection.
Define alignment tolerance and the temperature cycle.
03 / CFRP
Lightweight frames & booms
Straight members in portable equipment and small UAV structures, subject to the complete assembly design.
Identify bending, vibration, torsion and impact cases.
Design the ends as carefully as the tube
Spread the load
Review bonded fittings, sleeves or supported inserts to transfer load without concentrating pressure on a thin wall. Holes and cutouts interrupt fibers and need their own assessment.
Specify the interface
Define adhesive, bond preparation, fit, cure and inspection. Where carbon meets aluminum or other susceptible metals in wet service, use suitable electrical isolation and sealing.
Validate the assembly
Agree static, fatigue or environmental testing for the actual fitting and tube. Include service temperature, chemicals, UV exposure and impact in the requirements.
Carbon fiber tubing questions
What is a pultruded carbon fiber tube?
It is a hollow, constant-section composite made by pulling resin-impregnated carbon reinforcement through a heated die. The main fibers typically run along the tube. This architecture supports longitudinal stiffness, while the resin and any off-axis reinforcement govern other aspects of performance.
How does pultruded tubing differ from roll-wrapped carbon tubing?
Pultrusion pulls reinforcement continuously through a die. Roll wrapping places prepreg plies around a mandrel, allowing selected fiber angles. A mainly unidirectional pultrusion can suit axial and bending duties; significant torque or circumferential loads may need an architecture with off-axis plies. Compare the actual laminate and test data, not just the process name.
Which carbon tube sizes and tolerances can I order?
Send the required outside and inside dimensions, wall, finished length, fit and quantity. F1 reviews the section, tooling and inspection requirements before confirming dimensions and tolerances. This page does not represent a fixed stock-size list; sample timing, MOQ and production lead time are quoted for the proposed configuration.
Is a carbon fiber tube electrically insulating?
No. Carbon fibers are electrically conductive. If electrical isolation is required, start with a suitable fiberglass tube specification and qualify the complete part under the required electrical and environmental conditions. A surface coating alone should not be assumed to provide dependable insulation.
Can I drill, clamp or bond pultruded carbon tubing?
These details require joint design. Drilling interrupts fibers, and concentrated clamp pressure can split or crush a thin wall. Define load transfer, bond preparation, supported inserts or sleeves, adhesive and environmental exposure; validate the finished connection. Do not apply a universal clamp torque or bond length.
Can these tubes carry internal pressure?
A structural carbon tube has no implied pressure rating. Pressure service requires a purpose-designed hoop reinforcement system, end connections and qualification. Include pressure, temperature and medium in the brief so the manufacturing route can be reviewed.
Send your carbon tube drawing
Start with your section, finished length, quantity and the job the tube needs to do. We reply within one business day; a formal quotation follows once the specification and delivery are reviewed.
- Drawing & fit
- OD / ID, wall, cut length, tolerances and mating components.
- Loads & service
- Span, axial and bending loads, torque, clamp loads, deflection and exposure.
- Material & evidence
- Fiber, resin, surface preparation and the inspection or test plan.
- Quantity & delivery
- Trial and repeat quantities, destination and required date.