What are B surface blades?
Rotor blade manufacturing is a very intricate process where the layers of carbon fiber must be applied in a "perfect" fashion and in an undisturbed environment in order to achieve a perfect finish. It is widely known in industries that work with carbon fiber for manufacturing that attempting to achieve perfection is almost impossible. Therefore, during any production cycle, factories will often end up with different "grades" of product finishes. In the case of Switch, "A" grade blades, also known as "Premium Carbon Fiber Blades" are 100% structurally sound and 99%+ percent cosmetically perfect, in some rare cases there might be some very small, almost invisible blemishes, such as tiny little bubbles or gelcoat imperfections on the surface, but are almost always unnoticeable to the naked eye.
"C" grade blades are those that are compromised during the manufacturing process, and are unsafe because are not structurally sound, these blades are always discarded and thrown away.
Last, but not least, "B" grade blades, also known as "B Surface" or "Blemished Blades" are those blades that came out of the production line in good health, they're structurally strong and safe to fly, but ended up with small blemishes. These cosmetic flaws are more visible and in most cases can be seen with the naked eye. These could just be gelcoat imperfections, tiny chips or cracks, and even very small air bubbles. These blades are again 100% structurally sound and perfectly safe to fly, so why waste them? We usually have the factory "store" these for a certain period of time until enough are produced (unintentionally of course) and then bring them in for sale. They're sold to us at a reduced price, and we pass the savings on to you!
Please note that these blades are sold "AS-IS" as we cannot "search" for a "better finish", they're all packaged exactly the same as our Premium blades are and all sales are final!
Here are some examples of blemishes you can expect to see: