Collection: Diamond Wire Hollow Drill Bits

Professional micro diamond wire hollow core drill bits for precision drilling of glass, gemstone, ceramic, and hard brittle materials. The hollow core design allows water to flow directly through the drill center for continuous internal cooling at the cutting zone, producing clean, chip-free holes without overheating. Available in 1.0mm to 4.0mm diameters, 65mm length, in economical 20pcs sets at $15.00 per set. Always use with continuous water lubrication through the hollow core or in a shallow water bath for optimal results and extended bit longevity.

Available Sizes & Pricing

Hollow Core vs Solid Diamond Drill Bits

Compatible Applications

• Gemstone bead drilling — agate, jasper, quartz, turquoise, jade
• Glass bead and pendant drilling — fused glass, borosilicate, stained glass
• Ceramic and porcelain micro-hole drilling
• Lapidary pendant and jewelry stone drilling
• Fossil and mineral specimen drilling for display mounting
• Compatible with drill presses, flex shaft machines, and rotary tools with water feed

Related Tools

• Diamond Core Drill Bits — Larger hollow core drills for bigger holes in stone and glass
• Sintered Diamond Drill Bits — Long-life sintered bits for production drilling
• Solid Diamond Drill Bits — Solid electroplated bits for general drilling
• Water Swivel Adaptors — Water feed adaptors for hollow core drilling on rotary tools
• Diamond Carving Burs — Fine carving and engraving burs for stone and glass

Frequently Asked Questions

• Q: How does the hollow core design improve drilling performance?
  A: The hollow center of the drill bit allows water to be fed directly through the drill shank and out through the cutting tip during drilling. This provides continuous internal cooling at the cutting zone, the most critical area where heat builds up. Compared to solid bits where water is applied externally, hollow core bits maintain lower temperatures at the tip, producing cleaner holes with less chipping and significantly extending bit life on delicate materials like glass and gemstone.
• Q: What diameter should I choose for gemstone bead drilling?
  A: For standard gemstone beads, 1.0mm–1.5mm bits produce holes suitable for fine wire and thin cord. For standard bead cord and stringing wire, 1.8mm–2.0mm is the most common size. For heavier cord or leather, use 2.5mm–3.0mm. Always drill from both sides of the stone to meet in the middle, preventing blowout on the exit side and producing clean holes.
• Q: How do I set up water feed through the hollow core?
  A: Use a water swivel adaptor mounted on your drill press or rotary tool, allowing the bit to rotate while water is fed through the stationary water inlet. Alternatively, drill in a shallow water bath where the water level covers the drilling area, allowing capillary action to draw water through the hollow core.
• Q: What materials are these bits suitable for?
  A: Diamond wire hollow core bits are suitable for glass (fused, stained, borosilicate), gemstone (agate, jasper, quartz, turquoise, jade), ceramic, porcelain, and other hard brittle materials. The hollow core water cooling makes them particularly effective for delicate materials where heat buildup would cause cracking or chipping.
• Q: Why buy 20pcs sets instead of individual bits?
  A: At $15.00 per 20pcs set, the per-bit cost is $0.75, making these economical for production bead drilling and jewelry making where bits are consumed regularly. Having multiple bits of the same size allows continuous drilling without stopping to wait for a single bit to cool, and provides immediate replacements when bits wear out during production runs.