We get a wide range of questions about how to use our carbon fiber plate. This page is dedicated to answering the most commonly asked questions. These questions and answers are designed to help you succeed in making your part! However, our answers are based on our own experience and opinion. Hillside Composites LLC assumes no responsibility for the use, misuse, and/or results of either, as related to any materials, product(s), information, and/or suggestions. 

Below are a list of commonly asked questions. If you don't see your question, contact us!

+ What is carbon fiber?

Carbon fiber is an extremely stiff and strong fiber. Carbon fiber starts out as an organic polymer with high carbon content, such as polyacrylonitrile (PAN) or pitch. The polymer is extruded into long fibers, washed, and stretched to acheive the desired diameter. These long strands are then chemically altered in order to convert their linear atomic bonding to ladder bonding. Next, the fibers are heated to very high temperatures, up to 5500°F, causing the non carbon atoms to be expelled, and the carbon atoms to align. The surface of the carbon fiber is oxidized in order to roughen the surface for improved mechanical bonding, and then coated to protect them from damage during the winding process. These fibers are most often woven into a fabric and are then ready for use in composite part manufacturing.

+ What is carbon fiber reinforced plastic (CFRP)?

Carbon fiber in fabric form is not very useful. It must be used to reinforce some other material. The most common material reinforced with carbon fiber is plastic (CFRP). The same principals apply in fiberglass materials, except CFRP is substancially stronger and lighter. The most common plastics used are Epoxy and Polyurethane. In some high temp applications other materials like ceramic or graphite are used.

+ What are the pros and cons of CFRP?


  • Light Weight
  • High Strength to weight ratio
  • Fiber orientation can be customized
  • Corrosin Resistant
  • Chemical Resistant
  • Extremely Low thermal expansion
  • Non Magnetic
  • Radiolucent
  • Opaue to visible light
  • Unique and visually striking aesthetic
  • Fatigue resistant


  • Typical max temperature is around 170F
  • Plastic degrades in UV light
  • Suceptable to moisture
  • Difficult to machine
  • Abrasive on cutting tools
  • Carbon fiber dust is conductive
  • Expensive
  • Low heat conduction
  • Does not yeild

+ What are the applications for carbon fiber?

Common applications are found in structural applications where high strength, high stifness, and low weight are critical. However, there are a multitude of other appications that take advantage of other unique properties of carbon fiber. Below are some examples:

Robotics, UAVs and Drones, Boat making, Aircraft Parts, Manufacturing fixtures, Electronics Enclosures, Radar Structures, Medical Applications, X-ray and Gamma ray applications, Scientific Equipment, Military, Sporting goods, Luxury, Musical Enstruments, Furniture, Art, and much more.

+ Can I get a sample of carbon fiber plate?

We sell 1inch x 6inch samples of our standard carbon fiber here: http://www.hillsidecomposites.com/standard-carbon-fiber-plate We also sell 6inch x 6inch peices of most other carbon fiber plate, cored panels, and veneers. We provide free samples to select companies and return customers on a limited basis.

+ Can i get a piece of carbon fiber plate cut to the size i need?

If you are ordering less than 24"x24", the most economical choice is to buy from the stock sizes available. If you order 1 full sheet (24"x48"), we will make four cuts for free. Additional cuts, and cuts on small pieces incur a charge.

+ Can i get a custom shape cut from carbon fiber plate?

We can machine carbon fiber parts to your specifications. Send us a detailed drawing of your part and we will provide you with a fast quote.


+ How do composite manufacturers cut carbon fiber?

The most common methods used in professional manufacturing are CNC routing and water jet cutting.

CNC Routing results in the highest edge quality and part accuracy under the right conditions. Cut quality is sensetive to improper feed rate and depth settings, cutting tool material, geometry, lifespan, and holdown methods. Poor cut quality is represented by excessive burrs, heat damage, and innacurate cuts. CNC Routing also offers 3 dimensional machining operations not available with waterjet cutting.

Waterjet cutting is faster and more economical for some mass produced parts; However, this method is very sensetive to feed rate and peircing operations, often resulting in delamination due to the high pressures jet used. This method is also generally limited to larger parts, or parts with tabs due to the nature in which parts are secured.

Laser cutting is not good for cutting CFRP due to heat damage. Carbon fiber and plastic have two extremely different thermal properties, and the carbon fiber/plastic matrix has poor heat cunduction. The laser cuts the plastic much faster than the carbon fiber, causing heat damage.

+ How do i cut and drill carbon fiber on a budget?

For one offs, prototypes, people on a budget, and non dimensionally critical parts, cutting parts by hand is a good way go. A Dremel tool with a flex shaft attachment is a great choice for cutting and shaping carbon fiber plate. You can basically cut any profile in carbon fiber plate with just a few dremel bits.

  1. Preparation: Sketch out your desired part on the back of the carbon fiber plate. Secure the plate so that it can be cut easily without holding it. Be careful not to get a carbon fiber splinter after cutting and before sanding.
  2. Saftey: Always wear safety glasses, a respirator, and rubber gloves. You should also cut it outside away from people. A shop vac can be very helpful in capturing the dust while it is created. Carbon fiber is itchy like fiberglass when cut, so a long sleeve shirt is recomended.
  3. Tools: Dremel with flex shaft with the following dremel tools: a thin diamond blade for making straight cuts, a carbide burr for shaping, a sanding drum with 120 or 220 grit for shaping and sanding, inexpensive disposable drill bits. You will also need some sandpaper, preferably silicon carbide.
  4. Methods: Use the abrasive cutting wheel to cut straight lines. Diamond cutting wheels produce the best results in carbon fiber. When you need to cut thick carbon fiber plate, use a tile saw or jigsaw with a diamond blade. For shaping, a solid carbide burr is ideal for making small features while a 120 or 220 grit sanding wheel is good for shaping larger smoother features. Finish the edge of your part with a piece of 220 grit sandpaper to smooth it out and use a sanding block to make flat edges flatter. Drill your holes slowly, and with breaks to avoid heat build up. Use inexpensive drill bits as they will become dull rapidly.

+ How do i know what thickness to use?

CFRP is not isotropic, meaning the mechanical properties are not the same in all directions. It is also not homogenious meaning that it is made up of different materials oriented in varying configurations. For that reason it is very difficult to compare the strength and stiffness of a composite material to homogenious materials like mild steel or 6061-T6 aluminum. The lest expensive method for determining what thickness sheet to use for small projects is experimentation. Start with a thickness equal to that of the part in aluminum, and test. For larger projects we recomend that you consult with a composites engineer. Contact us for more information about our engineering services.

+ What is the density of carbon fiber?

Density of various materials:

  • Plastic: 1.17g/cm3
  • CFRP: 1.44g/cm3
  • Fiberglass: 2.58g/cm3
  • Aluminum: 2.70g/cm3
  • Titanium: 4.54g/cm3
  • Steel: 7.60g/cm3
  • Stainless Steel: 7.90g/cm3

+ What is the strength to weight ratio of carbon fiber?

Specific strength of various materials:

  • Plastic: 1.17g/cm3
  • CFRP: 1.44g/cm3
  • Fiberglass: 2.58g/cm3
  • Aluminum: 2.70g/cm3
  • Titanium Alloy (Beta C): 4.81g/cm3
  • Steel: 7.60g/cm3
  • 304 Stainless Steel: 7.90g/cm3

+ How strong is carbon fiber?

Ultimate strength of various materials:

  • Plastic: 1.17g/cm3
  • CFRP: 1.44g/cm3
  • Fiberglass: 2.58g/cm3
  • Aluminum: 2.70g/cm3
  • Titanium: 4.54g/cm3
  • Steel: 7.60g/cm3
  • Stainless Steel: 7.90g/cm3

+ How stiff is carbon fiber?

Youngs modulus of various materials:

  • Plastic: 1.17g/cm3
  • CFRP: 1.44g/cm3
  • Fiberglass: 2.58g/cm3
  • Aluminum: 2.70g/cm3
  • Titanium: 4.54g/cm3
  • Steel: 7.60g/cm3
  • Stainless Steel: 7.90g/cm3

The stiffness of a material is defined by Young's Modulus, and a higher value represents greater stiffness. A typical Young's Modulus for carbon fiber is 128GPa, 6061-T6 Aluminum is 69GPa, and Mild Steel is 210GPa. However, for carbon fiber, that value is only valid along the length of the fiber. Further, carbon fiber must be encased in an epoxy matrix in order to utilize it for

+ What type of glue should i use on cabron fiber?

We recoment that you use a structural adhesive such as Loctite Hysol 9340, or 3M Scotch weld DP110, DP420, or DP420NS. Use a fillet of epoxy to strengthen corners.

+ Can i bend carbon fiber?


+ What is the difference between standard and quasi isotropic carbon fiber plate?


+ What is are the pros and cons of using cored panels?