Carbon Fiber Rod Selection Guide — How to Choose Carbon Fiber Rods ?
Lightweight, High‑Strength & Customizable “Linear Frame” Solutions
Version: 2025‑07‑25 | For Online Sizing Tool & Engineer Quick‑Reference
1. Product Definition
A carbon fiber rod is a solid or thin‑walled circular profile made by pultrusion or compression molding of continuous carbon fibers impregnated with resin. With fibers aligned along the axis, carbon fiber rods deliver exceptional specific strength and stiffness, making them ideal replacements for aluminum, steel or wood linear structural members.
2. 3‑Step Selection Method (30 s)
- Determine Loads (Tension/Compression/Bending)
- Select Diameter & Tolerance
- Match Fiber Grade & Surface Finish
Lock in your carbon fiber rod in 30 s; generate a DFM report in 5 min.
3. Quick‑Reference Specifications
| Nominal Diameter (mm) | Common Tolerance | Linear Mass* (g/m) | Recommended Length (mm) | Typical Applications |
|---|---|---|---|---|
| 1.0–2.0 | ± 0.05 mm | 1.2–4.5 | 100–1,000 | Medical needles, model linkages |
| 3.0–4.0 | ± 0.05 mm | 10–18 | 500–2,000 | UAV tail‑booms, instrument neck braces |
| 5.0–6.0 | ± 0.10 mm | 30–45 | 500–3,000 | Camera rigs, robot skeletons |
| 8.0–10.0 | ± 0.10 mm | 75–120 | 1,000–4,000 | Civil reinforcement, space trusses |
| 12–20 | ± 0.15 mm | 180–500 | 1,000–6,000 | Wind‑turbine webs, bridge cables |
*Calculated for T300 epoxy at Vf = 60%.
4. Fiber Grade & Mechanical Properties
| Grade | Tensile Strength (MPa) | Modulus (GPa) | Density (g/cm³) | Keywords |
|---|---|---|---|---|
| T300 | 3,530 | 230 | 1.55 | General‑purpose, cost‑effective |
| T700 | 4,900 | 230 | 1.60 | High‑strength, UAV |
| T800 | 5,490 | 294 | 1.60 | Aerospace, racing |
| M40J | 4,410 | 377 | 1.63 | Ultra‑modulus, optical fixtures |
5. Surface Finish Options
| Finish Type | Gloss Level | Features | Use Cases | Extra Cost |
|---|---|---|---|---|
| 3K Twill Glossy | 90 GU | Mirror‑like texture, showcase‑grade | Premium models, instruments | + 8 % |
| 3K Twill Matte | 15 GU | Anti‑fingerprint, low glare | UAVs, camera equipment | Base price |
| UD Matte Black | 5 GU | No visible weave, ultra‑light | Industrial structures | – 5 % |
| Color Silk‑Screen | — | Brand logos & scale markings | Racing, surveying tools | + 10 % |
6. Tolerance Classes
| Class | Diameter Tolerance | Straightness | Length Tolerance | Inspection Method |
|---|---|---|---|---|
| P0 | ± 0.02 mm | 0.2 mm/m | ± 0.5 mm | Laser diameter gauge |
| P1 | ± 0.05 mm | 0.5 mm/m | ± 1 mm | Go/No‑Go gauges |
| P2 | ± 0.10 mm | 1.0 mm/m | ± 2 mm | Calipers |
7. Key Manufacturing Processes
- Pultrusion: 0° fiber alignment, tight diameter tolerance, endless length cuts.
- Compression Molding: Ideal for large diameters or custom cross‑sections; higher mechanical performance.
- Secondary Machining: CNC slots, tapping, laser marking, metal end‑insert integration.
8. Joining & Assembly
| Connection Method | Features | Tooling |
|---|---|---|
| Epoxy Bonding | Fast, no threads required | AB adhesive + fixtures |
| Metal Inserts | Repeated disassembly & reassembly | Mold‑in aluminum sleeves |
| Rivets & Bolts | High‑load capacity | Drilling + rivet nuts |
9. Application Scenarios Snapshot
- UAVs: Tail‑booms, arm reinforcement, landing gear struts
- Robotics: Linear actuator frames, lightweight linkages
- Civil Engineering: CFRP rebar, bridge stay cables
- Musical Instruments: Guitar & ukulele neck stiffeners
- Medical: External fixation rods, biopsy needles
- RC Models: Chassis, tail booms, control rods
10. Selection Example (60 s)
Scenario: Hexacopter tail‑boom, 300 mm length
- Diameter: 4 mm
- Fiber Grade: T700
- Finish: 3K Twill Matte
- Tolerance: P1
→ Result: 5.4 g rod weight (– 68 % vs. aluminum), + 40 % resonance frequency.
11. Online Tool & Delivery
- Rod Calculator: Input loads & length, get recommended diameter in 30 s.
- Stock Diameters (1–12 mm): Ships in 48 h.
- Custom Rods (0.5–30 mm × 50–6,000 mm): 7 days lead time.
- Services: CNC deep machining, integrated metal end‑caps.
12. Common Pitfall Warnings
- “Larger diameter equals safer” → increases weight, lowers resonance frequency.
- Ignoring straightness → long rods bend easily; choose P0 for critical precision.
- Torsion applications → rods can split under torque; consider square tubes or hybrid structures.
By selecting the right diameter, fiber grade & finish, every carbon fiber rod becomes a “gram‑Newton” performance multiplier.
Access our online rod sizing tool now and secure your custom solution in 30 seconds!
