Tek screw size chart: point numbers and drill capacity
Tek is the ITW brand name that became the generic word for self-drilling screws: screws with a drill-bit point that bores their own hole into steel, then tap their own threads, in one driving motion [6]. The spec that actually decides whether the job works is not the screw size, it is the point number: the #1 through #5 ladder that sizes the drill point, and with it the maximum total steel thickness the screw can drill before its threads start tapping [6]. That ladder lives almost entirely inside manufacturer PDFs, so this chart is built on the three first-party rails that publish it in full: the ITW Buildex TEKS catalog matrix, the DeWalt metal construction screw technical guide, and the Grabber self-drilling selection guide [1][6][7]. If you are new to the category, our self-tapping vs self-drilling screws page covers what each term actually means; this page is the numbers.
The three numbers on every Tek screw
Read a callout like 10-16 x 3/4 HWH #3 left to right and you have the whole screw [1]:
| Part of callout | Example | Means | Range |
|---|---|---|---|
| Diameter and thread | 10-16 | #10 nominal size, 16 threads per inch (coarse) | #6 through 5/16 in; each diameter has a coarse and sometimes a fine thread [6] |
| Length | x 3/4 | nominal length in inches | 1/2 through 8 in by part [1] |
| Head style | HWH | hex washer head | HWH, pan, wafer, flat, pancake and more [6] |
| Drill point | #3 | the drill point size, the load-bearing choice | #1 through #5 (plus 4.5) [1][6] |
The one rule everything else hangs off, stated independently by DeWalt and Grabber: the drill point must pass completely through the base metal before threads begin tapping [6][7]. Grabber's version of why: screw threads advance up to ten times faster than the drill flute can remove metal, so if the first thread engages while the point is still cutting, the screw binds, the point burns up or breaks, and the connection is ruined [7]. Pick the point for the total thickness of all steel layers plus any spacing between them; pick the length for that thickness plus a minimum of three full threads protruding past the back side [6][7].
Main matrix: screw size x point number x drill and tap capacity
The heart of the chart. Column pairs are the minimum and maximum combined steel thickness each screw size and point can drill and tap, taken from the Buildex TEKS Drill and Tap Material Thickness Chart and set against the DeWalt maximum drilling capacity chart [1][6]. Every load-bearing row carries both first-party surfaces, and the Buildex matrix is stable across printings: the 2020 and March 2026 catalog editions carry identical values in all 13 columns [1][3].
| Screw size | Point | Min thickness (in) | Max thickness (in) | Gauge territory | Sources |
|---|---|---|---|---|---|
| #10 | Teks/1 | .018 | .095 | 26 to 20 ga | [1][6] |
| #12 | Teks/1 | .018 | .095 | 26 to 20 ga | [1][6] |
| 1/4 | Teks/1 | .018 | .095 | 26 to 20 ga | [1][6] |
| #8 | Teks/2 | .036 | .100 | 20 to 18 ga | [1][6] |
| #10, #12, 1/4 | Teks/2 | .036 | .110 | 20 to 18 ga | [1][6] |
| #10 | Teks/3 | .036 | .175 | 20 ga to 1/8 in approx | [1][6] |
| #12 | Teks/3 | .036 | .210 | 20 ga to 3/16 in approx | [1][6] |
| 1/4 | Teks/3 | .036 | .210 | 20 ga to 3/16 in approx | [1][6] |
| #12 | Teks/4 | .125 | .250 | 1/8 to 1/4 in | [1][6] |
| 1/4 | Teks/4 | .125 | .250 | 1/8 to 1/4 in | [1][6] |
| #12 | Teks/4.5 | .125 | .250 | 1/8 to 1/4 in | [1][6] |
| 1/4 | Teks/4.5 | .125 | .250 | 1/8 to 1/4 in | [1][6] |
| #12 | Teks/5 | .125 | .500 | 1/8 to 1/2 in | [1][6] |
| 1/4 | Teks/5 | .125 | .500 | 1/8 to 1/2 in | [1][6] |
| #6 | #2 | .018 | .095 | 26 to 20 ga | [2][6] |
| #8 | #2 | .024 | .095 | 24 to 20 ga | [2][6] |
How the two rails disagree, printed rather than averaged [1][6]:
| Cell | Buildex TEKS chart | DeWalt chart | Reading |
|---|---|---|---|
| #8 / #2 point max | .100 | .095 (lapped 18-18 ga exception) | DeWalt is more conservative; use .095 for double-layer 18 ga [1][6] |
| #10-#12-1/4 / #2 point max | .110 | .100 | same direction, DeWalt lower [1][6] |
| 1/4 / #4 point max | .250 | .312 | DeWalt allows more; Buildex caps 1/4 at .250 and reserves .312-.375 for #12 and 5/16 hardware [1][6] |
| #10 / #1 point range | .018-.095 (with #12, 1/4) | .095 max, #10-#12-1/4 group | the two rails print the same group with #10 included; Buildex column shows the shared min-max band [1][6] |
Two footnotes the charts carry. First, both makers stamp a variability warning on the matrix: drill and tap capacities may vary with special feature designs, so the product part list is final for a specific part number [1][6]. The same capacity ladder extends to dissimilar-metal work: DeWalt's Bi-Flex bi-metal structural screws carry the same #2/#3/#5 point logic with separate aluminum drilling and tapping capacities alongside steel [4]. Second, Buildex's own TEKS selection chart prints real parts whose band edges extend the matrix: several 12-14 and 1/4-14 Teks/3 parts carry a .036-.210 capacity band, and the heavy 12-24 and 1/4-28 Teks/5 structural parts run .125-.500 [1]. When a specific part number's published capacity differs from the generic matrix, the part number wins.
Screw size ladder: nominal size to decimal diameter
The diameter decoder every chart assumes you already know. Three of the four surfaces print the same ladder to the thousandth; Buildex prints two cells differently, disclosed below [1][6][7][8].
| Nominal size | Decimal (in) | mm | Standard thread | Sources |
|---|---|---|---|---|
| #6 | .138 | 3.51 | #6-20 coarse (no fine) | [6][7][8] (Buildex prints .140) [1] |
| #8 | .164 | 4.17 | #8-18 coarse (no fine) | [6][7][8] (Buildex prints .160) [1] |
| #10 | .190 | 4.83 | #10-16 coarse, #10-24 fine | [1][6][7][8] |
| #12 | .216 | 5.49 | #12-14 coarse, #12-24 fine | [1][6][7][8] |
| 1/4 | .250 | 6.35 | 1/4-14 coarse, 1/4-20 fine | [1][6][7][8] |
| 5/16 | .3125 | 7.94 | 5/16-18 coarse, 5/16-24 fine | [6][7][8] |
| 3/8 | .375 | 9.53 | 3/8-16 coarse | [6][7] |
Grabber's basic-diameter table extends the same ladder down to #0 (.060 in) and up through 5/8 in (.625 in), and it is the rail worth using when you need the odd in-between sizes: #7 is .151, #9 is .180, #14 (which Grabber does not list but Albany carries at .242 in with 14-20 thread) sits between #12 and 1/4 [7][8]. The TPI guidance that comes with it: coarse threads for thinner material, finer threads for thick material, because fine threads tap into thick base metal with lower installation torque [6].
The Buildex divergence, printed rather than hidden: their catalog's decimal equivalents column reads #6 .140, #8 .160, #11 .200, #12 .210, #13 .230, #14 .240, #17 .286 [1], while their own competitors and the dealer ladder agree on .138/.164/.190/.216 for the common sizes [6][7][8]. Buildex's column is nominal-with-rounding; treat the three-surface values as the working decimals and expect Buildex printings when quoting Buildex part numbers.
Length ladder and the sizes that actually ship
Dealer size ladder from Albany County Fasteners, the second surface for what is on the rack [8]:
| Size | Common lengths | Common points | Typical use | Sources |
|---|---|---|---|---|
| #6 | 1/2, 3/4, 1 | Tek 1, Tek 2 | light HVAC, thin panels | [8][2] |
| #8 | 1/2, 3/4, 1, 1-1/4 | Tek 2 | HVAC, light metal framing | [8][2] |
| #10 | 3/4, 1, 1-1/2, 2 | Tek 2, Tek 3 | metal studs, standard roofing | [8][2] |
| #12 | 1, 1-1/2, 2, 3 | Tek 3, Tek 4 | metal roofing, framing | [8][2] |
| #14 | 1-1/2, 2, 2-1/2, 3 | Tek 3, Tek 4 | heavy roofing, structural | [8] |
| 1/4 | 1-1/2, 2, 3, 4 | Tek 4, Tek 5 | structural steel, thick metal | [8] |
| 5/16 | 2, 3, 4, 6 | Tek 5 | heavy structural, equipment | [8][6] |
| 3/8 | 3, 4, 6 | Tek 5 | maximum duty applications | [8] |
Length selection rule, three-surface consensus: the screw must penetrate all layers plus a minimum of three full threads past the back of the base steel, and DeWalt formalizes the same rule as the minimum protrusion length in its part tables [1][6][7]. Albany's working guidance is at least 3/8 in of engagement in the base material [8]. For drywall and other gauge-thread territory, our drywall screw sizes page carries the equivalent ladder for sharp-point screws.
Gauge to decimal decoder: the two charts people confuse
Tek charts quote steel in gauge numbers, and there are two different gauge charts in circulation. The Buildex sheet steel chart is the reference for panel and sheet work [1]:
| Gauge | Decimal (in) | mm | Sources |
|---|---|---|---|
| 30 | .012 | .30 | [1] |
| 28 | .015 | .38 | [1] |
| 26 | .018 | .45 | [1][6] |
| 24 | .024 | .61 | [1][6] |
| 22 | .030 | .76 | [1][6] |
| 20 | .036 | .91 | [1][6] |
| 18 | .048 | 1.21 | [1][6] |
| 16 | .060 | 1.52 | [1][6] |
| 14 | .075 | 1.90 | [1] |
| 12 | .105 | 2.65 | [1][6] |
| 1/8 in | .125 | 3.18 | [1] |
| 10 ga | .134 | 3.42 | [1] |
| 3/16 in | .187 | 4.77 | [1] |
| 1/4 in | .250 | 6.36 | [1] |
| 1/2 in | .500 | 12.72 | [1] |
The structural steel stud chart is different, and using the sheet chart to check a stud specification is a real error. Grabber publishes the ICBO AC 46 version: a nominal 20 ga stud is .0329 in minimum thickness / .0346 in design thickness (33 mil), 18 ga is .0428/.0451 (43 mil), 16 ga is .0538/.0566 (54 mil), 14 ga is .0677/.0713 (68 mil), 12 ga is .0966/.1017 (97 mil), and 10 ga is .1180/.1240 (118 mil) [7]. Note the design thickness rule printed with it: design thickness equals minimum thickness divided by 0.95 [7]. So 16 ga sheet steel is .060 in but a 16 ga structural stud is .0538 in minimum; when a drill capacity table says a point handles .036 to .210 in, measure the actual steel, do not convert the gauge in your head.
DeWalt's tech pages print their own nominal sheet metal size list (26 ga .018 through 12 ga .105), which matches the Buildex sheet chart value for value on the shared rungs [6][2].
The wing rules: wood over metal, verbatim
Winged screws solve wood-over-metal: reaming wings above the drill point bore an oversized clearance hole through the wood so the threads cannot grip it, and the wings snap off when they hit steel, letting the threads tap into the metal below [6][7]. The trap is minimum steel thickness. ITW Buildex prints the two rules that decide whether the wings break, quoted verbatim [1]:
All #10 diameter Winged parts must be driven into a minimum of 16 GA steel thickness.
All 1/4 and #12 diameter Winged parts must be driven into a minimum of 1/8 in steel in order to break the wings consistently.
Drive a winged #10 into 20 ga steel and the wings will not snap; the screw keeps reaming an oversized hole and never bites [1]. Grabber's selection guide adds the wood-side limit: if the wood is over 1/2 in thick, a clearance hole is required, and their winged fasteners break off on contact with a minimum .090 in steel surface [7]. Buildex's wood-to-metal TEKS line (10-24, 12-14, 1/4-20 with Teks 3 and Teks 4 points) is built around exactly this regime [1].
Installation rules that come with the chart
Speed and pressure, from the maker tables [1][6][7]:
| Diameter | Max installation RPM | Sources |
|---|---|---|
| #6 | 2500 | [2][6] |
| #8, #10, #12 (points 1-3) | 2500 (#12 drops to 1800 with points 4, 4.5, 5) | [2][6] |
| #12 with point 4, 4.5 or 5 | 1800 | [2][6] |
| 1/4 and 5/16 | 1200 | [2][6] |
The rest of the consensus: install perpendicular with a depth-sensitive nosepiece (Buildex specifies a 6 amp minimum, 0-2500 RPM screwgun for TEKS; Grabber's ESR-1271 report caps installation at 2500 RPM with three exposed threads minimum) [1][5]; too little pressure prolongs drilling and too much burns the point [6]; and the flute rule explains most burned points: the flute is the chip channel, and if it becomes fully embedded in material the chips have nowhere to go, cutting stops, and the point burns up or breaks [7]. That is the mechanism behind the matrix: a #5 point is not stronger, it is longer, with a longer flute to keep cutting through .500 in of steel.
Related guides
Also on this site: self-tapping vs self-drilling screws for the category definitions, drywall screw sizes for the sharp-point gauge ladder, tap drill chart when the hole is headed for a machine thread, pilot hole chart for wood and self-tapping work, and SDS bit sizes for the masonry side of the drill point world.
Sources
- ITW Buildex, TEKS selection catalog PDF, March 2026 printing (pulled live 2026-09-24): Drill and Tap Material Thickness Chart (13 screw size x point columns, Teks/1 through Teks/5, .018-.095 up to .125-.500), nominal screw decimal equivalents (#6 .140 through 1/4 .250), steel gauge chart (30 ga .012 through 1/2 .500), TEKS selection chart part rows (.036-.175 and .036-.210 Teks/3 bands, 12-24 and 1/4-28 Teks/5 .125-.500), wing rules verbatim (16 GA minimum for #10 winged, 1/8 in minimum for 1/4 and #12 winged), installation instructions (6 amp 0-2500 RPM screwgun, 3 thread pitches minimum penetration):: buildex.ca
- DeWalt Anchors, Drilit tech page PDF (pulled live 2026-09-24): point size selection table with RPM by diameter (#6 2500 through 5/16 1200, #12** 1800 note for points 4/4.5/5), nominal sheet metal sizes 26-12 ga, screw size decimals #6 .138 through 5/16 .3125, drilling and tapping capacity chart:: anchors.dewalt.com
- ITW Buildex, Steel-to-Steel TEKS catalog PDF, 2020 printing (pulled live 2026-09-24): independent second printing of the same Drill and Tap Material Thickness Chart and gauge chart, all 13 columns identical to the March 2026 printing:: buildex.ca
- DeWalt Anchors, Bi-Flex tech page PDF (pulled live 2026-09-24): point size selection with drilling and tapping capacity including aluminum column, nominal sheet metal sizes 25-12 ga, screw decimals #8 .164 through 1/4 .250:: anchors.dewalt.com
- ICC-ES Evaluation Report ESR-1271, Grabber self-drilling tapping screws (pulled live 2026-09-24): installation requirements (2500 RPM maximum, perpendicular installation, three exposed threads minimum protrusion), screw dimensional table with drilling capacities by part:: grabberpro.com
- DeWalt Anchors, Screw Fasteners tech guide PDF (metal construction screw technology, 2024) (pulled live 2026-09-24): maximum drilling capacity chart by point (#1 .095 through #5 .500 with the 5/16 column), point-must-pass-completely-through rule, diameter decimals #6 .138 through 5/8 .625, TPI coarse/fine table, RPM guidance, head styles, winged reamer and Type 17 point definitions:: anchors.dewalt.com
- Grabber Construction Products, Product Specification Manual PDF, self-drilling screw selection guide section (pulled live 2026-09-24): steel metal gauge table (minimum and design thickness, 33/43/54/68/97/118 mil), screw size basic diameter table (#0 .060 through 3/8 .375), drill flute embed rule (chips trapped, point burns up or breaks), point length rule (threads advance up to 10x faster than the flute removes metal), drilling through wood to metal rule (over 1/2 in wood needs clearance hole, wings break on minimum .090 in steel):: grabberpro.com
- Albany County Fasteners, Self-Drilling Screw Guide (Fasteners 101) (pulled live 2026-09-24): dealer size ladder (#6 .138 through 3/8 .375 with common lengths, typical points and uses), point type summaries, engagement and selection guidance, downloadable tek point selection guide:: albanycountyfasteners.com