Glass & Tile Drill Bits

Glass + Tile Drill Bit Selection — Quick Reference

Drilling glass + ceramic + stone requires SPECIALIST bits — standard twist drills shatter glass / chip tile glaze / slide without cutting. Glass + tile bits use SPEAR-POINT tungsten carbide OR DIAMOND abrasive cutting mechanism.

Critical drilling rules: 1) Use WATER cooling — keeps bit + tile cool + flushes debris; 2) LOW speed — 200-500 RPM (high speed = chips tile + dulls bit); 3) LIGHT pressure — let bit cut at own pace; 4) Start hole with masking tape over tile to prevent bit walking; 5) For diamond bits: water cooling MANDATORY (dry-cut destroys bond + diamonds quickly). NEVER use hammer drill on tile — shatters glaze + cracks tile. Brands: Sutton Tools, Bordo. Companion: drilling, diamond saw blades, masonry drill bits.

Glass & Tile Drill Bits

Drilling glass, ceramic tiles, and stone requires a completely different drill bit to those used for wood and metal. Standard twist drills cannot cut these materials — they would either shatter the glass, chip the tile glaze, or simply slide without cutting. Specialist glass and tile drill bits use either a spear-point tungsten carbide tip or diamond abrasive to abrade through the material without applying the shear cutting action that would crack hard, brittle substrates. AIMS Industrial supplies glass and tile drill bits for construction, glazing, plumbing, and electrical work requiring holes in ceramic, glass, and stone surfaces.

Spear-Point (Lance-Tip) Bits

Spear-point drill bits have a tungsten carbide tip ground to a flat, spear-shaped profile. The tip applies a scraping abrasion action rather than a cutting action, gradually abrading through the tile or glass surface. They are the standard for drilling wall tiles, floor tiles, and flat glass — quick to set up and effective on most domestic and commercial ceramic and porcelain tile work. Key technique requirements: use a slow drill speed (300–800 RPM is typically appropriate), steady moderate pressure, and coolant (water or cutting fluid) to prevent overheating of the tip and thermal cracking of the glass or tile. Never use percussion (hammer) mode on glass or tile — the impact will shatter the material.

Diamond Core Drill Bits

Diamond core bits use a diamond-impregnated matrix on the cutting edge to abrade holes in hard materials. They are specified for larger diameter holes (typically 6mm and above) in porcelain, granite, marble, and hard ceramic tiles where spear-point bits would be too slow or would wear before completing the hole. Wet diamond core drilling uses water as a coolant to extend bit life and control dust. Diamond bits are significantly more expensive than spear-point bits but last much longer in appropriate materials and produce cleaner holes in hard, abrasive substrates.

Technique and Safety

Starting a hole in smooth glass requires a guide or starting template to prevent the bit from wandering before it has abraded into the surface. A rubber suction guide filled with water serves as both a starting guide and a coolant reservoir. Wear eye protection — glass fragments and tile chips are a significant eye hazard. For glass and tile drill bit selection by material and hole size, contact our team.

For drilling into frameless glass, tempered glass requires specialist drilling before toughening — it cannot be drilled once tempered. Always confirm the glass type before attempting to drill. Contact our team for product recommendations specific to your substrate.

People Also Ask — Glass and Tile Drill Bits

Q: What's special about glass and tile drill bits?

Glass and tile drill bits use carbide spear-point geometry or diamond-coated tips — designed to cut hard brittle materials (porcelain, ceramic, glass) without cracking the workpiece. Standard HSS twist drills don't work on these materials — they slip, chip, or shatter the work. Diamond-coated core drills cut clean holes in dense porcelain tile, granite countertops, and glass. Spear-point carbide bits work on standard ceramic tile and softer glass.

Q: Carbide spear-point or diamond core — which?

Carbide spear-point: cheaper, works on softer ceramic tile and standard glass, good for occasional use. Diamond core (with central pilot pin or with hollow centre): essential for porcelain tile (much harder than ceramic), granite, marble, and dense modern tiles. Diamond cores cost more but last 10-50× longer in hard materials. For workshop kit covering tile installation work, both have a place — carbide for soft tile, diamond for porcelain/stone.

Q: How do I drill glass without cracking it?

Critical technique: use water cooling continuously (run a small dam of water around the hole or wet sponge), use a spear-point bit or diamond core, run at LOW RPM (300-600 RPM, not 2000+), apply VERY LIGHT pressure, and tape the surface to prevent the bit from skating. For thicker glass (>10mm), drill from both sides — start the hole, flip the glass, finish from the other side to prevent exit chipping.

Q: Can I use the same bit on tile and glass?

Spear-point carbide bits work on both ceramic tile and glass — yes for general workshop use. Diamond core bits work on porcelain tile, granite, glass, and stone — versatile but expensive. For dense porcelain tile, dedicated porcelain-rated diamond cores cut faster than general-purpose diamond. Match the bit to the hardest material you'll cut — porcelain bits work on softer materials but soft-tile bits don't work on porcelain.

Q: What size hole for a tile-mounted fixture?

Match drill bit diameter to the fixture mount: 6mm for standard wall-anchor + screw, 8-10mm for grab rails and heavier fixtures, larger for tap and waste outlets. For tile, drill the hole, then drill through to the substrate (timber stud or concrete behind tile) with the appropriate substrate-specific bit. Don't drill into solid masonry with a tile bit — different bit needed for the masonry behind. For tap/plumbing fittings, use dedicated tile hole-saws.