Collection: Sintered Diamond Core Drills

Sintered Diamond Core Drills – Long-Life Metal Bond Core Drills for Stone, Glass & Ceramic

Professional sintered metal bond diamond core drills for precision drilling of stone, glass, ceramic, granite, marble, and hard materials. Unlike electroplated core drills where diamonds are surface-coated only, sintered core drills have diamond particles embedded throughout the entire metal matrix — delivering significantly longer service life and consistent cutting performance throughout the tool's life. Available from 3mm through 100mm diameter. Always use with water cooling.

🔥 Shop Sintered Diamond Core Drills – From $8.00

Available Sizes & Pricing

Diameter Price
3mm – 9mm $8.00 – $12.00
13mm $9.50
15mm $10.50
17mm $11.50
18mm $12.00
30mm $19.00
58mm $33.00
59mm $33.50
99mm $56.00
100mm $58.50

Sintered vs Electroplated Core Drills

Feature Sintered (Metal Bond) Electroplated
Diamond bond Throughout metal matrix — self-sharpening Surface layer only
Service life Very long — production use Shorter — economical for light use
Best for Hard stone, granite, marble, production drilling Glass, ceramic, occasional use
Cost per hole Lower — longer life Higher — shorter life

Diameter Selection Guide

Diameter Range Typical Application
3mm – 9mm Gemstone drilling, pendant holes, small jewelry stone drilling
13mm – 18mm Standard pendant bails, medium jewelry holes, tile drainage holes
30mm Large pendant holes, decorative stone cutouts, tile access holes
58mm – 59mm Sink cutouts in stone countertops, large tile cutouts
99mm – 100mm Large stone slab cutouts, countertop sink holes, architectural stone

Compatible Applications

  • Granite and marble countertop drilling — sink cutouts, faucet holes
  • Stone tile drilling — drainage holes, fixture mounting
  • Gemstone and lapidary stone drilling for jewelry
  • Glass drilling — plate glass, tempered glass (with appropriate speed)
  • Ceramic and porcelain tile drilling
  • Compatible with drill presses, magnetic drill stands, and angle grinders with water swivel adaptors

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Frequently Asked Questions

  • Q: What is the advantage of sintered core drills over electroplated core drills?
    A: Sintered core drills have diamond particles embedded throughout the entire metal matrix — as the cutting surface wears, fresh diamonds are continuously exposed (self-sharpening). This gives sintered drills 5–10× longer service life than electroplated drills where diamonds are only on the surface layer. For production drilling on hard stone (granite, marble, quartzite), sintered drills are significantly more economical per hole drilled despite the higher upfront cost.
  • Q: What diameter sintered core drill do I need for a sink cutout?
    A: For standard kitchen sink cutouts in granite or marble countertops, the 58mm–59mm drills are used for the corner radius cuts, and the 99mm–100mm drills are used for larger circular cutouts. For faucet holes, 30mm–35mm is the most common size. Always verify the required hole diameter with your sink or fixture specifications before ordering.
  • Q: Do sintered core drills require water cooling?
    A: Yes — always use water cooling with sintered core drills. Water prevents heat buildup in the metal bond matrix, extends drill life, and produces cleaner, chip-free holes. Use a water swivel adaptor for continuous internal water feed through the hollow core, or build a clay dam water reservoir around the drilling area for smaller drills.
  • Q: What drill speed should I use for sintered core drills?
    A: Use lower RPM for larger diameter drills and harder materials. As a general guide: 3mm–9mm at 1,500–3,000 RPM; 13mm–30mm at 600–1,500 RPM; 58mm–100mm at 300–600 RPM. Always use consistent light-to-medium pressure — never force the drill. Let the diamond abrasive do the cutting.
  • Q: Can sintered core drills be used on tempered glass?
    A: Tempered glass cannot be drilled after tempering — the internal stress will cause the glass to shatter. Holes in tempered glass must be drilled before the tempering process. For non-tempered plate glass, sintered core drills work effectively with water cooling and slow, consistent feed pressure.