Diamond Core Bits for Granite, Marble & Natural Stone | Pro Tool Haus

Granite, marble, quartzite, and other natural stone materials require diamond core bits with specific bond hardness matched to the stone's abrasiveness. Granite — one of the hardest and most abrasive stone types — demands a softer bond that continuously exposes fresh diamond; marble and limestone are softer and require a harder bond to prevent the segments from wearing too quickly. 

The core bits in this collection cover the most common countertop drilling applications: 1-3/8" for standard faucet holes, 1-1/4" for European faucets, 1-1/2" for side spray holes, and larger diameters for soap dispensers and drain installations. All rated for wet drilling with a water swivel attachment. 

Always drill at low RPM (500–800 for granite) with steady light pressure — high speed and heavy pressure are the primary causes of core bit failure. For the water swivel attachments needed for wet drilling see Water Attachments.