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   Woolen Felt is a non-woven formation, relying on his characters- wool phosphorus. Through pressure, heat, and humidity, the wool becomes felt. There are many advantages of Felt, thermal insulation as traditional usages, but also flexible, hard to lose, and can be cut into various shapes of parts as the polishing bobs and wheels ..etc.

   Cross-section of wool is as hard as rock, and can be used for grinding materials itself.

   Felt can be an effective carrier particle. Felt polishing wheel and bobs have better capability than other materials to accept the various polishing compounds and slurry. Abrasive particles are distributed evenly in the capillaries of the felt, which uniformly polished the required surface. Sheep wool is considered to be the best natural fibers of resilient material, because it can maintain its edge and shape through his life. As felt wears, the new surface has an identical medium of polishing compound because the felt surface does not get glazed. When the felt surface wears, a new surface has formed and holds the polishing compound to continue the polishing work. The felt surface does not get glazed.

   Felt good wear resistance, excellent sharpness, can be used to make polishing bobs and wheels for polishing precision instruments, jewelry, glass, metal, and denture ...Etc.

   Felt density is calculated by the grams per cubic centimeter internationally, for example: Medium density is marked as 0.60 gram/cm³. Felt bobs and wheels are available in several densities. Soft (0.50 g/cm³), Medium (0.60 g/cm³), Hard (0.70 g/cm³) and Rock Hard (0.80 g/cm³). These densities are accepted worldwide. The people use to call the density by 0.50, 0.60, 0.70, 0.80, instead of the Soft, Medium, Hard, Rock hard.

   In the feltbobs.com, we most carried are 0.50, 0.60, 0.70, 0.80, which means Soft, Medium, Hard and Rock hard.

   It is very difficult to answer this question: which density is good for your work? It is mostly depending on what kind of metal you are going to polish, and what kind of polishing are you using. Here two things should be considered:

   1. How much polishing material do you want your felt bobs and wheels to hold?
The felt bobs and wheels with Soft density can hold more polishing material.
   2. What the surface conditions are are you going to polish?

   If the condition of surface is good, very little scratches, the hard density could be used. If the surface condition is not good, with significant scratches, then using a soft density of felt bobs and wheels.
Always remember: The softer the wheel, the better for high luster or final result.

   Felt bobs and Wheels can be attached to name-brand power tools like Black and Decker, Drexel, DeWalt, Makita and Ryobi. Large Felt Wheels can be attached to any bench grinder.

   We carry the felt bobs and mounted wheels in British measurement system and Metric system at feltbobs.com. The most of the power tools can hold both measurement systems.

In the British system of measurement, the felt bobs have 1/8” shank and ¼” shank at felt bobs.com. The felt bobs below ½” have 1/8” shanks. The felt bobs above ½” have ¼” shanks.

   In Metric system of measurement, the felt bobs have 3mm shank and 6mm shank at feltbobs.com. The felt bobs below 12mm have 3mm shanks. The felt bobs above 12mm have 6mm shanks. The felt mounted wheels below 25mm have 1/8” shanks. The felt mounted wheels above 25mm have 6mm shanks.

   The first few times you charge a new Felt Wheel or bob are going to be difficult as the polishing compound does not adhere well to clean felt.

   Here are a few tips to make charging easier:

   • While the Felt Wheel is stationary, hold the compound firmly against it. Start up the wheel but before it gains enough speed to throw off the freshly applied compound, shut the grinder off allowing the felt wheel to slow down. Repeat this procedure until the felt wheel is charged.

   • Another method involves an initial application of mineral oil to the felt wheel while it is spinning. Apply the oil lightly with a cloth. It is a good idea to stand aside when turning on the grinder as some excess oil or compound might fly off. After the oil is applied, hold the compound against the spinning felt wheel until the wheel is charged. It is not necessary to stop and start the grinder with this method.

   Your choice of charging method will be determined by the relative dryness of the compound you intend to use. After the The first few times you have charged the felt wheel, it will develop a the smooth surface of the old compound. Please resist the temptation to remove it as the build-up will make it easier to charge the wheel.

   With a little care, your Felt Wheels and Wheels can last a long time. At the end of your buffing and polishing, allow the felt wheel to continue to spin for several minutes so any remaining polishing compound residue can spit out. Then let the felt wheel air dry before storing it to prevent molds.

   Surface irregularities of the felt wheel will cause vibration and make accurate honing difficult. Felt Wheels are "trued" on both sides at the factory but it is a good idea to "true" your felt wheel if you are re-installing it or if you have been using it for a long period.

   It is a good idea to remove any surface irregularities from time to time to increase the life of a felt wheel.

   First, using a piece of bar stock or other square-edged steel item, remove any build-up of honing compound prior to "truing" the felt wheel as the compound will clog the sanding drum.

   Then mount a 1/2" sanding drum fitted with a 60x sleeve in an electric hand drill. With both the wheel and the drill spinning, bring the sanding drum against the wheel. Make light passes following the contour of the wheel's face and sides until the wheel is no longer eccentric and is restored to the desired condition.

   Check the arbor nuts on both sides of the grinder as braking action of "truing" the felt wheel might loosen them.

   In general, according to the polishing surface, you want to polish, you select the shape of felt bobs and wheels. The top and sides of the felt bobs, both can be used for polishing the contact surface.

   Bullet-shaped and cone-shape felt bobs are very similar. In feltbobs.com, we do not clearly distinguish the bullet-shaped cone-shape of felt bobs. For each product we have photos, photos are taken based on the actual product. You can see a photo to decide what you want for felt bobs.

   A little trick is: you can use fine sandpaper to change the shape of the felt bobs and wheels. The method is: first to mount the felt bobs or wheels to the Power rotary tool, and then carefully use the sandpaper to touch the part you do not need, remove that part.

If you still have difficulty finding the right felt bobs and wheels for you, you can take a picture sent to us by e-mail, our customer the service department will help you solve this problem.