Carbon Fiber Pultruded Rods
NitPro Composites manufactures solid pultruded carbon fiber rods built for applications that require maximum axial stiffness and compressive strength in a small, lightweight cross-section. Produced from unidirectional T700-equivalent carbon fiber bundles impregnated with epoxy or vinyl ester resin, our solid CFRP rods achieve 1600 MPa tensile strength and 135 GPa tensile modulus with ISO-verified mechanical data in diameters from 1 mm to 25 mm.
What Are Pultruded Carbon Fiber Rods?
Pultruded carbon fiber rods are fully solid cylindrical CFRP structures produced by the continuous pultrusion process. Unlike tubes, rods have no hollow core — every cross-sectional area is occupied by aligned carbon fiber and cured epoxy matrix. This solid construction delivers superior compressive strength and resistance to buckling over short unsupported lengths, making rods the preferred choice over tubes wherever the component is loaded in pure compression, used as a push-pull linkage, or required to resist lateral loads without buckling.
Material Specifications
| Parameter | Value | Unit |
|---|---|---|
| Diameter Range | 1 – 25 | mm |
| OD Tolerance | ±0.03 | mm |
| Fiber orientation | 0° Unidirectional | - |
| Fiber type | Standard Modulus CF (T700 equiv.) | — |
| Tensile strength | 1600 | Mpa |
| Tensile modulus | 135 | Gpa |
| Flexural strength | 175 | Gpa |
| Ultimate Tensile Strain | 1.30 | % |
| Glass Transition Temp (Tg) | 160 | °C |
| Density | 1.55 | gm/cc |
*All values evaluated by lab tests per ISO standards.
The Pultrusion Process for Solid Rods
Fiber Selection
Continuous carbon fiber bundles of T700-equivalent standard modulus are selected for the required diameter and mechanical performance.
Resin Impregnation
Fiber bundles are drawn through a controlled epoxy or vinyl ester resin bath, achieving a uniform resin distribution and high fiber volume fraction.
Die Forming and Cur
The impregnated fiber bundle is pulled through a precision heated die sized to the target rod diameter. The die simultaneously shapes and cures the composite, producing a dense, void-free solid cross-section.
Cutting and Finishing
Cured rods are cut to the specified length and ends are finished to customer requirements. OD tolerance of ±0.03 mm is maintained across production.
Applications
Robotics and Automation
Push-pull linkage rods, linear actuator inserts, and structural spine members in robotic arms.
Aerospace and Defense
Control linkage rods, antenna mast elements, and precision structural tie rods.
Sports and Recreation
Kite frame spars, RC aircraft control rods, bicycle brake rods, and archery arrow shafts.
Civil and Structural Engineering
Concrete reinforcement inserts, bridge deck tendon reinforcements, and post-tensioning rods.
Medical and Orthopedic
External fixator rods, pedicle screw fusion rods, and lightweight rehabilitation frame members.
Precision Instruments
Optical bench support rods, metrology frames, and camera slider guide rods.
Frequently Asked Questions
What is the smallest diameter carbon fiber rod available?
NitPro manufactures pultruded carbon fiber rods starting from 1 mm diameter, suitable for precision instruments, model aircraft control linkages, and micro-robotics.
What is the difference between a carbon fiber rod and a carbon fiber tube?
A rod is fully solid, providing higher compressive strength and suitability for axial push-pull loading. A tube is hollow, which reduces weight for a given bending stiffness — better for structural booms and frames. Rods are preferred when the component is in pure compression or must resist buckling over a short length
Can carbon fiber rods be used in medical or orthopedic applications?
Yes. NitPro produces CE/ISO-compliant carbon fiber orthopedic rods for external fixation and pedicle screw fusion, available from 4 mm diameter, 80 mm long to 5/16 inch diameter, 250 mm long.
How should carbon fiber rods be cut?
Carbon fiber rods should be cut using diamond-tipped or carbide-tipped cutting tools, abrasive disc cutters, or a dremel-type cutting wheel. Always use respiratory protection when cutting to avoid inhaling carbon fiber dust.
Are custom diameters between standard sizes available?
Yes. NitPro Composites can produce intermediate and non-standard diameters on request. Contact the sales team with your required diameter and length specifications.
What is the thermal limit of the standard rods?
The glass transition temperature (Tg) of the standard epoxy system is 160°C, establishing the upper continuous use temperature limit.