J-Weight Belts re the most flexible of the cotton backed belts available from AIS. As the name implies, they are about the weight of your average jeans. These belts are used primarily for applications where heavy stock removal isn’t necessary and where you want the belt surface to conform to the surface you are sanding, grinding or polishing. A perfect example is crankshaft polishing. With the various radii and curved surfaces that must be polished on a crankshaft, a highly flexible but durable belt is necessary and J-weight belts fit the bill perfectly.