FAQ – Carbon Fiber Tubes

Add On Services: How much do "Add-On" Services cost?

Add on services vary based on size, diameter, tolerances, etc. A price list can be found on our AddOns page.

Carbon Fiber vs. Metal: How does carbon fiber tubing compare to other materials?

This will though depend on the carbon fiber grade and laminate design. The differences can be seen on the “Properties of Common Carbon Fiber Laminate Designs vs. Metals” table on our “Properties of Carbon Fiber” page.

Drilling: Can I drill carbon fiber tubing?

Yes, carbon fiber tubes can be drilled. See below for helpful tips. -Bit: Jobbers carbide drill bit for composites (brad-point) -Spindle Speed: faster the better -Reinforce backside to prevent blowout. Can be done with tape, dowel, plug, or clamped to a sacrificial material

Galvanic Corrosion: Is galvanic corrosion a concern when bonding carbon fiber to metals?

Yes, carbon fiber is electrically conductive. Corrosion occurs by an electrochemical process where metal corrodes due to electrical contact, in the presence of an electrolyte. This can be prevented by insulating the tube with fiberglass (non-conductive). Often times, anodized aluminum and/or the epoxy layer can insulate enough to prevent galvanic corrosion.

Low CTE: What is the CTE of your carbon fiber tubes?

Carbon fiber laminates have low CTE compared to standard metals. Laminate design can be modified to make zero/specific CTE’s. Reach out to our sales team for additional information.

Machining: Can carbon fiber tubes be machined?

Yes, machining carbon fiber tubes is relatively straightforward. See below for helpful tips. -Bit: solid carbide router bit for composites, diamond if available – Spindle Speed: faster the better -Feed: based on thickness (proprietary) -Reinforce backside to prevent blowout. Can be done with tape, dowel, plug, or clamped to a sacrificial material

Mandrel List: I don't see the size I need on your product list. What other sizes do you offer?

We have a variety of mandrels in stock. See our mandrel list here: Clearwater Composites Mandrel List

Standard Tolerances: What are your standard tube tolerances?

Standard tube tolerances vary based on size, diameter, material, etc. Our standard tube tolerances can be found here: Standard Tube Tolerances

Temperature (Tg): What temperature can your tubing withstand?

Our standard, high, and ultra-high modulus tubes are made with standard 250° F cure epoxy pre-preg. We have not verified the Tg, but theoretical Tg is estimated at ~250° F.

Temperature (Tg): Is high temp material available?

We offer 350° cure, standard modulus, material as a custom solution. Higher temp material can be acquired but is on a per-part basis. Reach out to our sales team for additional information.

Twill vs. UD: What is the difference between the twill carbon fiber tubes and the UD carbon fiber tubes?

The simple answer – just the exterior ply of material. Unless noted on a specific product, all of our carbon fiber tubing is made with UD prepreg on the inside, and then will have either the UD exterior ply or a fabric ply. The twill carbon fiber fabric exterior is a popular choice as it provides the carbon fiber “look” that so many customers associate with carbon fiber.

Twill vs. UD: Are the twill carbon fiber tubes stronger or stiffer than the UD carbon fiber tubes?

Yes and no. It depends on the wall thickness and which property is of interest. If the tube wall thickness is the same, technical speaking, the UD exterior tubes will be slightly stronger and stiffer in bending (less than 10%). However, the hoop strength of the fabric exterior tubes will be slightly stronger. Again, this strength or stiffness increase is only a small percentage and will not be noticeable without precise testing equipment. It is advised customers choose between these options based on cosmetics, not strength. Another consideration is if holes are to be drilled into the tube, the twill exterior will resist splintering better than the UD exterior.

ROHS Compliance: Are your parts ROHS compliant?

Our standard carbon fiber prepreg is Considered ROHS compliant. A formal document can be sent upon request.