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Low-head socket cap screws: DIN 7984 M3–M20 and DIN 6912 (pilot recess) M4–M36 — head diameter and height, hex socket, thread length + head envelope models

What are the head size, height and hex key size of a DIN 7984 or DIN 6912 low-head socket cap screw? · Standard part · basis: Westfield Fasteners' DIN 7984 table (cross-checked against Ferrofast), fasten.it's DIN 6912 table (03-2021, Aspen Fasteners' table as a cross-check); seven DIN 7984 head envelopes as files

Also called: din 7984 dimensions, m6 low head cap screw head height, din 7984 m8 head diameter, low head socket cap screw m5 hex key size, din 6912 dimensions, m4 din 7984 hex socket size, low profile socket head cap screw m10 dimensions, din 7984 vs din 912 head height, din 6912 m6 pilot recess, m3 din 7984 head, low head cap screw m12 dk k s, din 7984 stl step

Exact dimensions. Every file is drawn at true size with no tolerance added. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your process's clearance before making the part. Mating features

length
5.5 mm
width
5.5 mm
height
14.0 mm

Notes

  • DIN 7984 (hexagon socket cap screws with low head, M3 to M20 here; the page lists to M24) in mm, from Westfield: pitch P; minimum thread length b for screws up to 125 mm long (b is longer for screws over 125 mm; the Westfield table has two more rows for that, not tabulated here); head diameter dk max / min; head height k max / min; socket s (nominal, with min / max on the source page) and socket depth t nominal (min – max); also shank ds, bearing face dw min, key corner e min, transition da max, edge radius r min, lf max and v max. The loadability of the low head is lower (Westfield: typically about 80 % of a standard 10.9 screw's); no strength values are tabulated here.
  • Ferrofast's DIN 7984 table agrees with Westfield on dk, s, t and the other k values, but prints k max 6.5 for M10 (Westfield 6.0), alongside a k min of 5.82 which cannot go with 6.5, and a key size s max of 12.212 for M18 below its s min; those two entries are treated as errors and Westfield's values are used. fasten.it's DIN 6912 table prints k max 6.5 at M10, the same as Ferrofast's 7984 row; the DIN 7984 value could be the older figure. Use the edition your drawing cites.
  • DIN 6912 (low head, with pilot recess) in the 03-2021 edition on fasten.it, M4 to M36, mm: P; b for three length ranges (≤ 125, > 125 to 200, > 200); dk max; k max; s nominal (socket); e min; dh min (the page's letter, read from the pilot-recess description as the recess diameter; not defined there); t1 nominal and t2 min (not defined either: socket and recess depths). The page says the 06-2009 edition has identical values, and that these screws have a short unthreaded portion of shank to make up for the pilot recess and a reduced loadability. Aspen's DIN 6912 sheet agrees on dk, k, s and the t values, but prints a dk min of 65.61 for M24 and a ds min of 65.61 for M36 (clearly errors, not used) and says it was compiled from public sources. Sizes in brackets in some sources (M14, M18, M22, M27, M33) are non-preferred.
  • Files: DIN 7984 M3 to M12 head envelopes: a plain cylinder of diameter dk max and height k max with a flat-bottomed hex socket of the nominal s across flats and depth t nominal, on a plain shank at the nominal diameter. The length under the head is 4 × d (12 to 48 mm), Xem's example, not a published length. No thread, no head edge radius, no conical socket bottom. No DIN 6912 file: the pilot-recess dimensions (dh, t1, t2) are not defined in the sources read.
  • McMaster-Carr sells pilot-recess (DIN 6912) screws and low-head socket screws with per-part STEP; its DIN 6912 and pilot-recess pages are linked, not copied. Standard-height socket screws: socket-head-cap-screws-metric, socket-head-cap-screws-inch-full.

Low-head socket cap screws: DIN 7984 M3–M20 and DIN 6912 (pilot… size chart

standard / sourcesizeP (mm)b min (L ≤ 125)head dia dk (max / min)head height k (max / min)socket s (AF)socket depth tother columns as printed
DIN 7984 (Westfield)M30.5125.5 / 5.322.0 / 1.8621.5 (1.38 – 1.62)ds 3 / 2.86; dw min 4.84; e min 2.3; da max 3.6; r min 0.1; lf max 0.51; v max 0.3
DIN 7984 (Westfield)M40.7147 / 6.782.8 / 2.662.52.3 (2.18 – 2.42)ds 4 / 3.82; dw min 6.2; e min 2.87; da max 4.7; r min 0.2; lf max 0.6; v max 0.4
DIN 7984 (Westfield)M50.8168.5 / 8.283.5 / 3.3232.7 (2.58 – 2.82)ds 5 / 4.82; dw min 7.7; e min 3.44; da max 5.7; r min 0.2; lf max 0.6; v max 0.5
DIN 7984 (Westfield)M611810 / 9.784.0 / 3.8243 (2.88 – 3.12)ds 6 / 5.82; dw min 9.2; e min 4.58; da max 6.8; r min 0.25; lf max 0.68; v max 0.6
DIN 7984 (Westfield)M81.252213 / 12.735.0 / 4.8253.8 (3.65 – 3.95)ds 8 / 7.78; dw min 12.03; e min 5.72; da max 9.2; r min 0.4; lf max 1.02; v max 0.8
DIN 7984 (Westfield)M101.52616 / 15.736.0 / 5.8274.5 (4.35 – 4.65)ds 10 / 9.78; dw min 15.03; e min 8.01; da max 11.2; r min 0.4; lf max 1.02; v max 1.0
DIN 7984 (Westfield)M121.753018 / 17.737 / 6.7885 (4.85 – 5.15)ds 12 / 11.73; dw min 17.03; e min 9.15; da max 13.7; r min 0.6; lf max 1.87; v max 1.2
DIN 7984 (Westfield)M1423421 / 20.678 / 7.78105.3 (5.15 – 5.45)ds 14 / 13.73; dw min 19.83; e min 11.43; da max 15.7; r min 0.6; lf max 1.87; v max 1.4
DIN 7984 (Westfield)M1623824 / 23.679 / 8.78125.5 (5.35 – 5.65)ds 16 / 15.73; dw min 22.83; e min 13.72; da max 17.7; r min 0.6; lf max 1.87; v max 1.6
DIN 7984 (Westfield)M182.54227 / 26.6710 / 9.78126.5 (6.32 – 6.68)ds 18 / 17.73; dw min 25.83; e min 13.72; da max 20.2; r min 0.6; lf max 1.87; v max 1.8
DIN 7984 (Westfield)M202.54630 / 29.6711 / 10.73147.5 (7.32 – 7.68)ds 20 / 19.67; dw min 28.83; e min 16; da max 22.4; r min 0.8; lf max 2.04; v max 2.0
DIN 6912 pilot recess (fasten.it 03-2021)M40.714; >125: —; >200: —7 (max)2.8 (max)3t1 1.6; t2 min 3.3e min 3.44; dh min 2
DIN 6912 pilot recess (fasten.it 03-2021)M50.816; >125: —; >200: —8.5 (max)3.5 (max)4t1 2; t2 min 4e min 4.58; dh min 2.5
DIN 6912 pilot recess (fasten.it 03-2021)M6118; >125: —; >200: —10 (max)4 (max)5t1 2.5; t2 min 5e min 5.72; dh min 3
DIN 6912 pilot recess (fasten.it 03-2021)M81.2522; >125: —; >200: —13 (max)5 (max)6t1 3; t2 min 6.5e min 6.86; dh min 4
DIN 6912 pilot recess (fasten.it 03-2021)M101.526; >125: 32; >200: —16 (max)6.5 (max)8t1 3.5; t2 min 7.5e min 9.15; dh min 5
DIN 6912 pilot recess (fasten.it 03-2021)M121.7530; >125: 36; >200: —18 (max)7.5 (max)10t1 4; t2 min 9e min 11.43; dh min 6
DIN 6912 pilot recess (fasten.it 03-2021)M14234; >125: 40; >200: —21 (max)8.5 (max)12t1 4.5; t2 min 10e min 13.72; dh min 7
DIN 6912 pilot recess (fasten.it 03-2021)M16238; >125: 44; >200: 5724 (max)10 (max)14t1 5.5; t2 min 11.5e min 16; dh min 8
DIN 6912 pilot recess (fasten.it 03-2021)M182.542; >125: 48; >200: 6127 (max)11 (max)14t1 6; t2 min 12.5e min 16; dh min 8
DIN 6912 pilot recess (fasten.it 03-2021)M202.546; >125: 52; >200: 6530 (max)12 (max)17t1 6.5; t2 min 14e min 19.44; dh min 10
DIN 6912 pilot recess (fasten.it 03-2021)M222.550; >125: 56; >200: 6933 (max)13 (max)17t1 7; t2 min 15e min 19.44; dh min 10
DIN 6912 pilot recess (fasten.it 03-2021)M24354; >125: 60; >200: 7336 (max)14 (max)19t1 7; t2 min 16e min 21.73; dh min 12
DIN 6912 pilot recess (fasten.it 03-2021)M27360; >125: 66; >200: 7940 (max)16 (max)19t1 8.5; t2 min 17e min 21.73; dh min 12
DIN 6912 pilot recess (fasten.it 03-2021)M303.566; >125: 72; >200: 8545 (max)17.5 (max)22t1 9; t2 min 19e min 25.15; dh min 15
DIN 6912 pilot recess (fasten.it 03-2021)M333.572; >125: 78; >200: 9150 (max)19.5 (max)24t1 10; t2 min 20e min 27.43; dh min 16.5
DIN 6912 pilot recess (fasten.it 03-2021)M36478; >125: 84; >200: 9754 (max)21.5 (max)27t1 11.5; t2 min 24e min 30.85; dh min 18

Mating features

Drawn at the exact size. Open press, slide, run and socket features by your process's clearance (tolerances by process); leave designed gaps and clamp fits as drawn.

featureexactmates withfitfiles
hex sockets across flats: M3 2, M4 2.5, M5 3, M6 4, M8 5, M10 7, M12 8 mm; depth t: 1.5, 2.3, 2.7, 3, 3.8, 4.5, 5 mmhex key of the same sizesocketdin-7984-*
shank (thread as plain cylinder)Ø3, 4, 5, 6, 8, 10, 12 mm (thread major)tapped hole of the thread, or a clearance hole (see socket-head-cap-screws-metric for clearance values)designeddin-7984-*
headØ dk max × k max: M3 5.5 × 2, M4 7 × 2.8, M5 8.5 × 3.5, M6 10 × 4, M8 13 × 5, M10 16 × 6, M12 18 × 7 mmcounterbore at least this wide and deep (the standards read give no counterbore size)designeddin-7984-*

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Westfield FastenersDIN 7984 hexagon socket cap screws with low head, M3 to M20: P, b, da, dk, ds, dw, e, k, lf, r, s, t, v (max / min)webDistributor reference; numbers only
Ferrofast (DIN fasteners)DIN 7984 low head socket head cap screws: thread length b1, head diameter d2, head height k, key size s, key engagement t (min / max), M3 to M24webDistributor reference; numbers only. Contains visible data errors (M10 k max / k min, M18 s)
fasten.itDIN 6912 Low head socket cap screws with pilot recess (03-2021, supersedes 06-2009): d, P, b, dk max, k max, s nom, e min, dh min, t1 nom, t2 min, M4 to M36webReference page; numbers only
Aspen FastenersMetric DIN 6912 spec: P, b, dk, da, dh, ds, dw, e, lf, k, r, s, t1, t2, v, M4 to M36 (page notes that it was compiled from public sources and may contain errors)webDistributor data sheet; numbers only
McMaster-CarrDIN 6912 pilot-recess socket screws (free STEP/IGES per part, for your own design use; no redistribution)STEP, IGES, PDFMcMaster-Carr site terms: personal design use, no redistribution verify
McMaster-CarrPilot-recess screws (free STEP/IGES per part, for your own design use; no redistribution)STEP, IGES, PDFMcMaster-Carr site terms: personal design use, no redistribution verify

Free files

★ Free files 7 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json

din-7984-m3-low-head-screw-envelopeDIN 7984 M3 low-head socket cap screw envelope: head Ø5.5 × 2.0 mm (dk max, k max), 2 mm hex socket 1.5 mm deep (t nominal, flat bottom), plain shank Ø3 × 12 mm under the head (example length, Xem's choice; no thread, no head edge radius, no chamfer)STEP · STL
din-7984-m4-low-head-screw-envelopeDIN 7984 M4 low-head socket cap screw envelope: head Ø7 × 2.8 mm (dk max, k max), 2.5 mm hex socket 2.3 mm deep (t nominal, flat bottom), plain shank Ø4 × 16 mm under the head (example length, Xem's choice; no thread, no head edge radius, no chamfer)STEP · STL
din-7984-m5-low-head-screw-envelopeDIN 7984 M5 low-head socket cap screw envelope: head Ø8.5 × 3.5 mm (dk max, k max), 3 mm hex socket 2.7 mm deep (t nominal, flat bottom), plain shank Ø5 × 20 mm under the head (example length, Xem's choice; no thread, no head edge radius, no chamfer)STEP · STL
din-7984-m6-low-head-screw-envelopeDIN 7984 M6 low-head socket cap screw envelope: head Ø10 × 4.0 mm (dk max, k max), 4 mm hex socket 3 mm deep (t nominal, flat bottom), plain shank Ø6 × 24 mm under the head (example length, Xem's choice; no thread, no head edge radius, no chamfer)STEP · STL
din-7984-m8-low-head-screw-envelopeDIN 7984 M8 low-head socket cap screw envelope: head Ø13 × 5.0 mm (dk max, k max), 5 mm hex socket 3.8 mm deep (t nominal, flat bottom), plain shank Ø8 × 32 mm under the head (example length, Xem's choice; no thread, no head edge radius, no chamfer)STEP · STL
din-7984-m10-low-head-screw-envelopeDIN 7984 M10 low-head socket cap screw envelope: head Ø16 × 6.0 mm (dk max, k max), 7 mm hex socket 4.5 mm deep (t nominal, flat bottom), plain shank Ø10 × 40 mm under the head (example length, Xem's choice; no thread, no head edge radius, no chamfer)STEP · STL
din-7984-m12-low-head-screw-envelopeDIN 7984 M12 low-head socket cap screw envelope: head Ø18 × 7 mm (dk max, k max), 8 mm hex socket 5 mm deep (t nominal, flat bottom), plain shank Ø12 × 48 mm under the head (example length, Xem's choice; no thread, no head edge radius, no chamfer)STEP · STL
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Plain text: sheet.txt · JSON: /api/geometry?object=low-head-socket-cap-screws-din-7984-6912

Low-head socket cap screws: DIN 7984 M3–M20 and DIN 6912 (pilot recess) M4–M36 — head diameter and height, hex socket, thread length + head envelope models, isometric render of a generated part
Render of din-7984-m6-low-head-screw-envelope from the free STEP; not to scale.

Fits with

Questions

What is the head height of an M6 DIN 7984 screw?

4.0 mm max and 3.82 mm min, head diameter 10 mm max (9.78 min), with a 4 mm hex socket 3 mm deep (Westfield).

What hex key fits an M8 low-head socket screw?

5 mm for DIN 7984 (head 13 mm × 5 mm); 6 mm for DIN 6912 (head 13 × 5 mm).

What is DIN 6912?

A low-head socket cap screw with a pilot recess (guide hole) in the head, M4 to M36; head dimensions equal DIN 7984's for M4 to M8 but the sockets differ (s 3, 4, 5, 6 against 2.5, 3, 4, 5 mm).