Collection: Sintered Drill Bits

Sintered Diamond Drill Bits & Burs – Long-Life Metal Bond Diamond Bits for Gemstones, Glass & Hard Stone

Professional sintered metal bond diamond drill bits and carving burs for drilling and carving gemstones, glass, tile, granite, and hard stone. Unlike electroplated bits where diamonds are surface-coated only, sintered bits have diamond particles embedded throughout the entire metal matrix — delivering significantly longer service life and consistent cutting performance throughout the tool's life. Available in multiple head shapes (ball, cylinder, cone, drum, inverted cone) and shank sizes (3mm, 6mm, 8mm). Always use with water cooling.

🔥 Shop Sintered Diamond Drill Bits – From $10.00

Available Sizes & Pricing

Product Type Head Size Shank Grit Price
Round Ball Bur Set (5pcs) H012 3–8mm 3mm 100 $30.00
Round End Cylinder Set (5pcs) H005 3–7mm 3mm 100 $30.00
Conical Point Bur Set (5pcs) H009 3–7mm 3mm 320 $30.00
Tapered Ball Nose Engraving Bit 8mm 8mm $35.00
Round-End Cylindrical Bur 10mm 6mm $16.00
Concave Bead Bur 12mm 8mm $18.00
Flat-End Grinding Burr 12mm 6mm $14.00
Flat Wheel Shape Bit 10mm 6mm $15.00
Flat Head Inverted Cone 10mm $10.00
Tapered Inverted Cone (small) 12mm $12.00
Tapered Inverted Cone (large) 24mm $19.00
Double Bevel Carving Bit 20mm $16.00
Drum-Shaped Grinding Drum (small) 35mm $35.00
Drum-Shaped Grinding Drum (large) 40mm $35.00
Flat-End Cylindrical Rotary Burr 10mm / 12mm 30–200 $85.00 – $90.00

Head Shape Guide

Shape Best For
Ball / Round Concave carving, bead shaping, interior curved recesses
Cylinder (flat end) Flat-bottom recesses, channel grinding, surface carving
Cylinder (round end) Smooth curved recesses, general carving
Conical / Tapered V-groove carving, engraving, pointed detail work
Inverted Cone Undercutting, dovetail recesses, inlay preparation
Drum Surface grinding, edge shaping on larger stone pieces
Concave Bead Bead groove grinding, consistent bead profile shaping

Compatible Applications

  • Gemstone carving and engraving — agate, jasper, quartz, turquoise, jade
  • Glass carving and surface texturing
  • Tile, granite, and ceramic drilling and carving
  • Stone bead groove grinding and bead profile shaping
  • Inlay preparation and undercutting on hard stone
  • Compatible with rotary tools (Dremel, Foredom), flex shafts, and drill presses

Related Tools

Frequently Asked Questions

  • Q: What is the difference between sintered and electroplated diamond drill bits?
    A: Electroplated bits have a single layer of diamonds bonded to the surface — once that layer wears through, the bit is finished. Sintered bits have diamonds embedded throughout the entire metal matrix — as the surface wears, fresh diamonds are continuously exposed, giving sintered bits 5–10× longer service life. Sintered bits cost more upfront but are significantly more economical for professional and production use.
  • Q: What shank size do I need for my rotary tool?
    A: Most Dremel-style rotary tools accept 3mm (1/8") shanks. Flex shaft machines and drill presses typically accept 6mm or 8mm shanks. Check your tool's collet size before ordering. The 3mm shank sets (H005, H009, H012) are compatible with most standard rotary tools.
  • Q: Do sintered diamond burs require water cooling?
    A: Yes — always use water cooling when carving or drilling with sintered diamond burs. Water prevents heat buildup that can damage both the bur and the workpiece, extends bur life significantly, and flushes away abrasive swarf for cleaner cuts. Use a water drip system, water swivel adaptor, or work in a water bath.
  • Q: What grit sintered bur should I use for gemstone carving?
    A: Use 30–80 grit for aggressive material removal and rough carving, 100 grit for general carving and shaping, and 150–320 grit for fine detail work and surface finishing. The 320 grit conical bur (H009) is particularly suited for fine engraving and detail carving on hard gemstones.
  • Q: Can sintered burs be used on glass?
    A: Yes — sintered diamond burs cut glass effectively for carving, engraving, and surface texturing. Use water cooling and light, consistent pressure. Avoid excessive downward force which can crack glass — let the diamond abrasive do the cutting.