Just the right hardness level for polishing steel tools, molds, and dies. These stones also double as a good choice for general polishing. Choose the stone shape that best matches the contour of your work surface. These stones can be used by hand or in a power tool with a holder (both sold separately). To keep debris from building up, apply a water-soluble or oil-based lubricant during use.

Aluminum oxide stones, also known as India stones, scrape away material slowly to give you more control over how much material you take off. They are good for the final stage of polishing.

Silicon carbide stones, also known as Crystolon stones, are extremely sharp. These stones remove material more quickly than aluminum oxide stones. They are best for the early polishing stage when you want to clear away more material from your work surface. However, they give you less control over material removal than aluminum oxide stones, so stopping at an exact point is more difficult to do.

Remove the tough scale left by the EDM (electrical discharge machining) process. These stones are harder than standard aluminum oxide polishing stones but are not so hard that they will scratch or gouge your workpiece. They abrade slowly, so you can control how much material you remove.

Polish by hand or use these stones in power tools with a compatible holder. You’ll also need lubricant.

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.

Remove high spots and even out gouges, leaving your surface flat enough for polishing. Made with a ruby abrasive, these stones have exceptional hardness and extra coarse grit to remove material faster than standard polishing stones. They also resist wear for long-lasting use. Use these stones by hand or in power tools with a compatible holder (both sold separately). Though not required, you can apply a water-soluble or oil-based lubricant to keep debris from building up.

Keep stones of different grits on hand to handle every stage of polishing on the smallest ribs, slots, and crevices. These stones are as thin as pencil lead, but stronger than they appear—made of bonded ceramic, they are tough yet flexible. They won’t snap like lead when you apply pressure. 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 (sold separately). To keep debris from building up, apply a water-soluble or oil-based lubricant during use.

Remove imperfections on tools, molds, and dies made from high-grade steel, such as P20 and H13 tool steel, 420 stainless steel, and more. These stones are harder than standard aluminum oxide stones. Thanks to their aluminum oxide abrasive, they slowly remove material to give you more control over how much you take off. Polish with them by hand or secure them in a power tool with the compatible holder. To stop debris from building up, apply a water-soluble or oil-based lubricant during use.