Glass and tile drill bit sizes: the carbide and diamond charts

A glass and tile bit is a spear-point carbide bit that grinds, rather than cuts, through brittle surfaces: ceramic tile, glazed tile, mirror, china, marble, and non-tempered glass. This page prints the actual size data by model number, all of it from manufacturer pages, catalogs, and cross-checked dealer listings: Bosch's ten GT singles, the Century, Artu, and Diablo carbide lines, the two Bosch sets and what they skip, and the DeWalt diamond ladder for porcelain [1] [6] [17]. For the how-to side, water setup and starting the hole without skating, see our guide to drilling glass and the tile drilling walkthrough.

Three things to know before reading the charts.

  • Model numbers do not encode the size in any rule you can trust. Dealer sites mislabel them constantly; we watched a GT300 dealer page carry GT800 spec text this week. Read the row, not the model arithmetic [1] [8].
  • Two material classes share the shelf: carbide spear points for ceramic and glass, and vacuum-brazed diamond for porcelain and natural stone. The tables are split the same way, because the lines are not interchangeable [5] [18].
  • Speed is the whole game: under 1,000 rpm general, under 500 rpm in hard ceramic, hammer mode off. The RPM section carries all three manufacturer positions [19] [20] [13].

Carbide chart A1: Bosch GT singles, all ten sizes

Bosch's GT line is the reference ladder for the category: ten individual bits spanning 1/8 through 1 inch. Diameters and total lengths below are from Bosch's own category page [1]. Cross-confirmations for the model-to-size mapping are in the sources list: Ohio Power Tool listings, Home Depot, Amazon, and Tractor Supply all agree with the factory table on every pair we checked [2] [3] [4].

Bosch GT glass and tile bits, singles
ModelDiameterTotal length (L2)
GT1001/8 in2 7/64 in
GT2003/16 in2 7/64 in
GT3001/4 in2 13/32 in
GT4005/16 in2 13/32 in
GT5003/8 in4 in
GT6001/2 in4 in
GT7005/8 in4 in
GT8003/4 in4 in
GT9007/8 in4 in
GT10001 in4 in

Two factory details worth knowing: every GT single uses a three-flat shank so the bit cannot spin in the chuck, and the GT800 spec sheet adds flute length 4 in with a 3/8 in minimum chuck for the 3/4 size [1] [4]. Note where the lengths step: the four smallest bits are short (2 7/64 and 2 13/32 in) and everything from 3/8 up is a 4-inch bit.

Carbide chart A2: Century, Artu PORC+, and Diablo DMANS

Three more carbide lines cover the same territory with different size runs. Century stops at 3/8; Artu's PORC+ (Porcelain Plus) line is built for hard porcelain and ships with a 5/32 pilot bit included; Diablo's DMANS bits are the impact-and-rotary exception covered below [9] [11] [15].

Other carbide glass and tile lines
MakerModelDiameterOverall lengthNotes
Century812123/16 in3 inQuad-cut copper-brazed tip, fluted shank [10] [11]
Century812161/4 inlength varies by seller, see noteDiameter solid everywhere; sellers split 4 in vs 2-1/4 in, so verify the listing [11] [12]
Century812205/16 in2-3/4 in3-flat shank [31] [14]
Century812243/8 inlength varies by seller, see noteDiameter solid everywhere; sellers split 3-1/2 vs 4 in [14] [10]
Artu PORC+014351/4 in4-1/8 inFlute 2-3/8 in; includes 5/32 pilot bit; carded number, bulk equivalent 01420 [15] [16]
Artu PORC+014405/16 in4-1/2 inFlute 2-3/8 in; includes 5/32 pilot bit; carded number, bulk equivalent 01422 [15] [16]
DiabloDMANS10301/4 in2-1/4 in3-flat shank; Diablo's page for this size says not for hammer mode [7] [8]
DiabloDMANS10405/16 in2-1/4 in3-flat shank [7] [9]
DiabloDMANS10503/8 in3-3/4 in3-flat shank; rotary and hammer rated [6] [7]
DiabloDMANS10601/2 in3-3/4 in3-flat shank; rotary and hammer rated [7] [32]

The two "length varies" rows are honest gaps, not laziness: for the Century 81216 and 81224, dealers publish two different overall lengths (True Value and Edge of Arlington say 4 in on both; Hardware World and Amazon say 2-1/4 and 3-1/2 in), and there is no first-party Century spec sheet to break the tie. The diameters are concordant everywhere, so buy on diameter and check the listing length against your needs [10] [11] [12] [14].

Not published on purpose: Century does not appear to make a 1/2 in glass and tile bit (their own available-sizes list tops out at 3/8), Diablo's DMANS1010 and 1020 sizes have no reliable public spec, and Bosch's NS natural-stone model numbers are printed without a verified size mapping. If a size is not in the tables above, we could not source it to two independent listings; verify before buying rather than trusting a decode rule [13] [7].

Diamond chart B: the DeWalt DW557x ladder

Porcelain and natural stone sit above what a carbide spear point can grind economically, and that is the diamond bit's job. DeWalt's DW557x line is the cleanest published ladder: nine sizes from 3/16 to 1-3/8 inch, vacuum-brazed diamond tips, reverse-spiral threads that pull water up into the cut, and core ejection slots so the plug pops out between holes [17] [21].

DeWalt diamond tile bits (DW557x)
ModelDiameterSecond source
DW55703/16 inMSC Direct listing and the Wesco catalog [22] [28]
DW55721/4 inMSC Direct and Mac's Hardware listings [22] [23]
DW55745/16 indewalt.com product page, Size 0.312 in [17]
DW55763/8 inMSC Direct and Mac's Hardware listings [22] [23]
DW55781/2 indewalt.com product page, Size 0.500 in [21]
DW55805/8 inHardware World and Home Depot listings [14] [24]
DW55823/4 inZoro and Acme Tools listings [25] [26]
DW55841 inHardware World listing and the Wesco catalog [14] [28]
DW55861-3/8 inToolmarts listing and the Wesco catalog [27] [28]

Every row is cross-confirmed by the Wesco DeWalt accessories catalog, which lists the full DW5570 through DW5586 ladder in one table [28]. Bosch's answer to this ladder is its own segmentation: NS natural stone carbide bits (impact-rated) for hard tile, then Porcelain Diamond bits with vacuum-brazing that Bosch rates at 10x longer bit life in porcelain than standard glass and tile bits, plus Hex Porcelain Tile Bits in between [5] [18]. Milwaukee rounds out the big three with its own ceramic and glass bits, 1/8 through 1/2 in, drill-driver only and not recommended for porcelain [29].

Bosch sets: GT2000 and GT3000, and what they skip

Both Bosch sets print their contents on the factory page, and both skip sizes the singles ladder carries [2]:

Bosch glass and tile bit sets
SetContentsWhat it skips
GT2000 (4 pc)1/8, 3/16, 1/4, 5/16 in; 2 in total length, 1.5 in working length3/8 and up, plus 7/8 and 1 from the singles ladder [2] [30]
GT3000 (8 pc)1/8, 3/16, 1/4, 5/16, 3/8, 1/2, 5/8, 3/4 in; 4 in total length, 3 in working lengthExactly 7/8 and 1 in [2] [30]

One nuance the factory pages print and most retailers gloss over: the 4-piece set's bits are shorter than the singles at the same diameter. A GT2000 bit is 2 in overall where the GT100 single is 2 7/64 in; the 8-piece set's 4 in total length matches the GT500-through-GT1000 singles exactly, so only the 4-piece shortens [1] [2]. If a hole needs to clear a thick tile plus substrate on a small diameter, buy the single, not the 4-piece set.

RPM and technique: the manufacturer positions

Speed and mode advice for glass and tile comes from three manufacturers' own pages, and they agree on the shape: slow, rotary only, cooled [19] [20] [13].

First-party RPM guidance for glass and tile bits
ManufacturerSpeedModeCooling
Bosch Professional (HEX-9 / CYL-9)gear 1, under 500 rpm corded; max 500 rpm if no gearsRotary only, never impactNot required; light wobbling in hard tile
Bosch DIYnot above 1,000 rpmHammer off, low pressureCool glass bit in cold water; spear bits to tile hardness ~3 (Mohs), diamond for porcelain
Century (manufacturer copy)300 to 800 rpmWithout hammer modeWet or dry

Bosch's professional guidance adds two details worth keeping: 15 to 20 kg of feed pressure is the right band, and you should hear a scraping noise when the bit engages, which confirms pressure and speed are right [19]. Artu's PORC+ technical bulletin adds the pilot-first method for its bits: drill a 5/32 pilot, step up to the final size, moderate pressure, cool between holes [16].

The hammer-mode exception, stated precisely: Bosch's guidance is rotary only, and that holds for every carbide spear point on this page except Diablo's DMANS 3/8 and 1/2, which Diablo and Home Depot both list for rotary and hammer drills. Diablo's own DMANS1030 page (1/4 in) carries a not-for-hammer-drills note, so the exception is per size, not per line; check the specific model before switching hammer on [19] [6] [7].

Choosing without overbuying

Most glass and tile work is fixture holes: towel bars, shower doors, mirror clips. That is 1/8 through 1/4 in territory, which every set and every line covers, and the Bosch GT2000 4-piece set is the honest default for it. Anchor holes in harder tile push 3/8 to 1/2, where you buy singles: a GT500 or GT600, or Diablo's DMANS1050/1060 if your drill collection is hammer-capable and the tile is thick. Porcelain and natural stone skip carbide entirely; the DeWalt diamond ladder or Bosch's Porcelain Diamond line is the tool, run slow with water. For the broader question of which bit family fits which surface, see drill bits by material; for anchor holes in the grout between tiles, the grout drilling guide; for speeds across every material, the drill speed chart; and for masonry anchor sizes once the hole is drilled, the masonry bit size chart.

Related pages

Sources

  1. Bosch, Glass & Tile Bits category (all 10 GT singles, diameter and total length L2): boschtools.com
  2. Bosch, Glass & Tile Bit Sets category (GT2000 and GT3000 contents, total and working lengths): boschtools.com
  3. Amazon, Bosch GT200 3/16 in carbide tipped glass, ceramic and tile drill bit (cross-confirmation of GT200 = 3/16): amazon.com
  4. Ohio Power Tool, Bosch GT800 3/4 in glass and tile bit spec sheet (flute length 4 in, min chuck 3/8 in, three-flat shank, carbide tipped): ohiopowertool.com
  5. Bosch, Tile Drill Bits category (line segmentation: Glass & Tile, Natural Stone, Porcelain Diamond, Hex Porcelain): boschtools.com
  6. Home Depot, Diablo DMANS1050 3/8 in tile, stone & glass carbide bit listing ("Use in corded & cordless rotary or hammer drills"): homedepot.com
  7. Diablo, DMANS product pages (first-party; DMANS1030 1/4 in 2-1/4 with not-for-hammer note, DMANS1040 5/16, DMANS1050 3/8, DMANS1060 1/2, Impact & Rotary Bits category): diablotools.com
  8. HVAC and Tools Direct, Diablo DMANS1030 1/4 in listing (diameter, 2-1/4 length, UPC 008925149439): hvacandtoolsdirect.com
  9. 1toptools, Diablo DMANS1040 5/16 in listing (5/16 diameter, 3-flat shank, 2-1/4 length): 1toptools.com
  10. Amazon, Century Drill & Tool 81212 3/16 in glass and tile bit (3 in overall length) and 81224 3/8 in listings: amazon.com
  11. Edge of Arlington Saw, Century glass & tile bits category (81212 3 in; 81224 4 in OAL in their spec table): eoasaw.com
  12. True Value, Century 81216 1/4 in x 4 in glass & tile masonry drill bit (spec table: 4 in length): truevalue.com
  13. Hardware World, Century glass and tile bits (81220 5/16 x 2-3/4; manufacturer copy "Use at low speed (300-800 RPM) without hammer mode"; Century available sizes list topping at 3/8): hardwareworld.com
  14. Hardware World, glass & tile bits category (Century 81224 3/8 x 3-1/2; DeWalt DW5580 5/8 and DW5584 1 in diamond tile bits): hardwareworld.com
  15. Artu, PORC+ Porcelain Plus drill bits spec table (01435 1/4 in OAL 4-1/8, 01440 5/16 in OAL 4-1/2, both incl. 5/32 pilot): artu.com
  16. Unilog, ARTU PORC+ Technical Bulletin PDF (01435/01440 specs, carded vs bulk 01420/01422 numbering, pilot-first method): unilogcorp.com
  17. DeWalt, DW5574 Tile Drill Bit product page (diamond tip, 5/16 in, size 0.312 in, reverse-spiral water feed, core ejection): dewalt.com
  18. Bosch, Porcelain Diamond Drill Bits (vacuum-brazing, 10x longer bit life in porcelain than standard glass and tile bits): boschtools.com
  19. Bosch Professional, CYL-9 / HEX-9 guidance (gear 1, under 500 rpm corded, rotary mode only, never impact, 15-20 kg pressure, no cooling required, wobbling in hard tile): bosch-professional.com
  20. Bosch DIY, drilling tiles guidance (speed not above 1,000 rpm, hammer off, low pressure, cold-water cooling, spear bits to hardness ~3, diamond for porcelain): bosch-diy.com
  21. DeWalt, DW5578 Tile Drill Bit product page (diamond tip, 1/2 in, size 0.500 in): dewalt.com
  22. MSC Direct, DeWalt PCD tile & glass drill bits (DW5570 3/16, DW5572 1/4, DW5576 3/8 with sizes; family page): mscdirect.com
  23. Mac's Hardware, DeWalt listings (DW5572 1/4 in and DW5576 3/8 in, 2-1/4 OAL): macshardware.com
  24. Home Depot, DEWALT masonry/tile drill bits category (DW5574, DW5578, DW5580 5/8, DW5582 3/4 diamond drill bits): homedepot.com
  25. Zoro, DeWalt DW5582 3/4 in diamond drill bit: zoro.com
  26. Acme Tools, DeWalt DW5582 3/4 in diamond drill bit: acmetools.com
  27. Toolmarts, DeWalt tile drill bits (DW5582 3/4 in, DW5586 1-3/8 in): toolmarts.com
  28. Wesco, DeWalt accessories catalog PDF (full DW5570-DW5586 diamond ladder): buy.wesco.com
  29. Milwaukee Tool, 5/16 in ceramic tile & glass bit 48-20-8983 (drill drivers only, not for porcelain; set 48-20-8988 spans 1/8 to 5/16, line to 1/2): milwaukeetool.com
  30. Toolmarts, Bosch GT3000 8-pc glass & tile set (contents 1/8 through 3/4): toolmarts.com
  31. Ace Hardware, Century 5/16 in x 2-3/4 in carbide tipped glass and tile bit, 3-flat shank, Mfr# 81220: acehardware.com
  32. Amazon, Diablo DMANS1060 1/2 in tile & stone carbide tipped drill bit: amazon.com