Smooth ribs, slots, teeth, and other fine features—these stones are thin enough to slip into hard-to-reach areas. Made of bonded ceramic, they’re harder and more wear resistant than aluminum oxide stones, but flexible enough not to crack under pressure. Pair with a holder (sold separately) to polish by hand or with a power tool, such as an ultrasonic polisher. Apply a water-soluble or oil-based lubricant to help keep debris from building up on the surface.

Keep stones in different grits on hand to smooth ribs, slots, teeth, and other fine features. The stones in these assortments are thin enough to slip into hard-to-reach areas. Made of bonded ceramic, they’re harder and more wear resistant than aluminum oxide stones, but flexible enough not to crack under pressure. Pair these stones with a holder to polish by hand or with a power tool, such as an ultrasonic polisher. Some holders are sold separately. Apply a water-soluble or oil-based lubricant to help keep debris from building up on the surface.

About the size of pencil lead, these stones polish your smallest ribs, slots, and crevices in molds and dies. Don’t underestimate their thin profile—they’re made of bonded ceramic, which makes them tough yet flexible. This means they won’t snap like pencil lead does when you apply pressure during polishing. These stones also resist wear, so they last a long time. Pair them with a holder to polish by hand or with an ultrasonic polisher (both sold separately). Apply a water-soluble or oil-based lubricant to help keep debris from building up on the surface.