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Drill bit for porcelain tiles

Updated: October 2026

The spare says porcelain, or the box says fully vitrified, and a ceramic spear is the wrong tool for that tile. This is the drill bit for porcelain tiles once you can name the material, from the Products Compared editorial team on 15 October 2026. It uses BS EN 14411, UK tile-shop guidance, and the amazon.co.uk listings in our [tile drill bits](/hub/drilling-and-accessories/tile-drill-bit) comparison. A purchase through our links can earn us a commission at no extra cost to you. Leave the generic spear in the drawer. A diamond set around £6 can still stop after a millimetre. Ceramic and glass stay on [diamond or carbide tile drill bit](/hub/drilling-and-accessories/tile-drill-bit/sub/tile-drill-bit-diamond-vs-carbide).

The spare says porcelain, or the box says fully vitrified, and a ceramic spear is the wrong tool for that tile.

Our top picks

BGTEC BGTEC 8-piece diamond hole-saw kit, up to 50 mm

Best overall

BGTEC BGTEC 8-piece diamond hole-saw kit, up to 50 mm
6.9/10about £39.99
View offer
SHDIATOOL SHDIATOOL 6 mm M14 dry diamond cores, pack of 2

Rank 2

SHDIATOOL SHDIATOOL 6 mm M14 dry diamond cores, pack of 2
8.8/10about £15.99
View offer
DKIBBITH DKIBBITH 7-piece dry diamond set, 5–12 mm

Alternative

DKIBBITH DKIBBITH 7-piece dry diamond set, 5–12 mm
8.3/10about £12.99
View offer
On this page
  1. 1.How you tell it is porcelain
  2. 2.What Topps and Homebuilding tell you to use
  3. 3.The carbide bit that is not a spear
  4. 4.What the listings in this comparison actually show
  5. 5.Depth, dust, and the floor you should not practise on

How you tell it is porcelain

You cannot read porcelain from the colour of the glaze. Checkatrade describes it as tile with water absorption of 0.5% or less, and it tells you to check the box. A shiny face and a water dab on the back are weak evidence. BS EN 14411 is the classification standard. ISO 13006 uses that same 0.5% figure, groups AIa and BIa, measured by ISO 10545-3. "Fully vitrified" on the pack is the shop phrase for that group. PEI is a glaze-wear class, separate from water absorption. If the box has gone, a spear that will not mark the glaze is a reason to stop.

What Topps and Homebuilding tell you to use

Topps Tiles says diamond for porcelain and stone, either wax-filled and dry or water-cooled and wet. The carbide spear stays with ceramic, because the point burns flat on porcelain. Homebuilding quotes Mark Irving the same way: a tungsten tip can ruin a porcelain tile. Rubi describes diamond as drilling porcelain by friction, so you cool the rim, and hammer mode can damage the tile. For a few bathroom plugs, Topps offers the wax-filled bit so you can work without a pumped feed. The drilling order is on how to drill into tile.
BGTEC BGTEC 8-piece diamond hole-saw kit, up to 50 mm

Testsieger

BGTEC BGTEC 8-piece diamond hole-saw kit, up to 50 mm
6.9/10about £39.99
View offer

The carbide bit that is not a spear

Bosch Professional sells the HEX-9 for hard ceramic and porcelain. You can drill it dry, on rotary only, and the centring tip can start without tape. Afterwards you change to a masonry bit. "Up to 10x" compares HEX-9 with Bosch CYL-9 only. Toolstation's 4–10 mm set sits outside the twelve listings here. A spear does not become a HEX-9 because the title says porcelain. QWORK, SabreCut, and HPMAISON are spears in this comparison, and porcelain in their copy does not change the tip. If you buy a spear from this basket, Topps still applies.

What the listings in this comparison actually show

Diamond is the family Topps names, and the reviews do not turn it into a guarantee. SHDIATOOL's 6 mm M14 bits, about £15.99 and 4.4 from 770 reviews, draw both finished porcelain holes and short life. That pair is the top pick here when you already own an angle grinder and the hole is 6 mm. DKIBBITH, about £12.99 and 4.3 from 414 reviews, shows hard-floor holes and leading-edge wear, on a round shank a chuck can hold. Zeeorymn, about £5.99, both cuts when cooled and fails to cut. BGTEC reaches 50 mm on a straight shank for an opening larger than a plug, at about £39.99, on a thin review file. SHDIATOOL is M14, so a drill needs an adapter the box does not include.

Depth, dust, and the floor you should not practise on

SHDIATOOL and LEKOMESH state a diamond height of 10 mm. That rim opens a wall tile and then stops. Bosch DIY's "typically 8–11 mm" is that article's rule of thumb for thickness. Fit a masonry bit once the porcelain is through, and leave hammer off until the tile bit is out. Hand the floor to a tiler when the tile is large-format, you have no spare, the floor is tanked, or underfloor heating may sit under the glaze. A day of dry coring is an employer's COSHH duty. One wall plug, with a spare and a clear detector reading, is a different job.

Common questions

How do you know a tile is porcelain?
Read the box. Checkatrade, with BS EN 14411 and ISO 13006, treats porcelain as fully vitrified tile with water absorption of 0.5% or less, in groups AIa and BIa. A shiny face and a water dab on the back are weak evidence. If a spear will not mark the glaze, stop. PEI 5 is a glaze-wear class, not that 0.5% figure.
Can you use a carbide spear if the packet says porcelain?
Leave a generic spear for ceramic. Topps says the point burns flat on porcelain, and a tungsten tip can ruin the tile. QWORK, SabreCut, and HPMAISON can print porcelain and still be spears. Bosch HEX-9 is the carbide sold for this material, and it is not in this basket.
Is a dry wax diamond bit enough for a few bathroom holes?
For a handful of plugs, Topps points at a wax-filled dry diamond bit, with no pumped feed. The wax melts as the rim heats, and you still pause when the glaze warms. A wet bit stays wet for the cut. Spray the tile and use a cordless drill.
Will a £6 diamond set get through porcelain?
It might, and the reviews here show that it might not. Zeeorymn at about £5.99 both succeeds when cooled and fails to cut. DKIBBITH at about £12.99 shows hard-floor holes and leading-edge wear. If the cut stops at about 1 mm, more pressure will not restore the edge.
What diameter do you need, and how deep is the diamond?
Match the millimetre mark on the plug. A red plug is often 6 mm when that number is printed on it. SHDIATOOL is that 6 mm only, on an M14 thread, with diamond height stated as 10 mm. You then need a masonry bit in the brick. Bosch DIY's 8–11 mm line is a rule of thumb in that article.

Related pages

Tile drill bit buying guide

Tile drill bits 2026

Best tile drill bit: who it fits, and who should skip

Diamond or carbide tile drill bit: one condition

How to drill into tile: tape, rotary, then masonry

Sources

Public UK sources and the amazon.co.uk listings in this comparison. Last checked 15 October 2026.

  1. Topps Tiles: what type of drill bit for tiles (retrieved 15 October 2026)
  2. Homebuilding: drilling into tile without cracking (retrieved 15 October 2026)
  3. Screwfix: how to drill into tile (retrieved 15 October 2026)
  4. Bosch Professional GB: EXPERT HEX-9 hard ceramic drill bit (retrieved 15 October 2026)
  5. HSE CIS36: silica dust when drilling and coring (retrieved 15 October 2026)
  6. BSI: BS EN 14411 ceramic tiles (retrieved 15 October 2026)
  7. Rubi: porcelain tile drill bits (retrieved 15 October 2026)
  8. amazon.co.uk listing B0751893Y2 (QWORK), checked 15 October 2026 (retrieved 15 October 2026)