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Light Hex Head Screw Plug Dimensions (DIN 7604 Forms A and C, M8x1 to M52x1.5)
Guide · Updated October 28, 2026
DIN 7604 covers light hexagon head screw plugs with collar, Form A and Form C, from M8x1 to M52x1.5. Values agree across HBS Solutions, Torqbolt, Globalfastener and Brassland. Check your supplier for critical work.
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Step by step
- Pick the form: Form A has a short spigot for shallow ports; Form C has a long spigot for deeper thread engagement.
- Check the pitch: DIN 7604 uses metric fine thread only (M8x1, M10x1, then x1.5).
- Pick the wrench: Use s from the chart; the low head is only m high, so use a 6-point socket.
- Seal it: Fit a DIN 7603 ring under the collar; from M18 the recess d3 locates it.
DIN 7604 light screw plug dimensions (mm)
Columns: form and thread, collar height c, collar diameter d2, recess diameter d3, width across corners e min, thread length i, overall length l (approx.), head height m, width across flats s (DIN 475-1), recess depth t.
- Size | c | d2 | d3 | e | i | l | m | s | t
- A M10x1 | 0.5 | 14 | — | 15.33 | 6 | 10.5 | 4 | 14 | —
- A M12x1.5 | 0.5 | 17 | — | 18.72 | 9 | 15.5 | 6 | 17 | —
- A M14x1.5 | 0.5 | 19 | — | 20.88 | 9 | 15.5 | 6 | 19 | —
- A M16x1.5 | 0.5 | 21 | — | 23.91 | 9 | 15.5 | 6 | 22 | —
- A M18x1.5 | 2 | 23 | 10 | 18.72 | 9 | 17 | 6 | 17 | 8
- A M22x1.5 | 2 | 27 | 14 | 20.88 | 9 | 17 | 6 | 19 | 8
- A M26x1.5 | 2.5 | 31 | 16 | 23.91 | 9 | 19.5 | 8 | 22 | 8
- A M30x1.5 | 2.5 | 36 | 20 | 23.91 | 9 | 19.5 | 8 | 22 | 8
- C M8x1 | 0.5 | 12 | — | 13.07 | 8 | 12.5 | 4 | 12 | —
- C M10x1 | 0.5 | 14 | — | 15.33 | 8 | 12.5 | 4 | 14 | —
- C M22x1.5 | 2 | 27 | 14 | 20.88 | 12 | 20 | 6 | 19 | 8
- C M26x1.5 | 2.5 | 31 | 16 | 23.91 | 12 | 22.5 | 8 | 22 | 10
- C M30x1.5 | 2.5 | 36 | 20 | 23.91 | 12 | 22.5 | 8 | 22 | 10
- C M38x1.5 | 3 | 44 | 26 | 23.91 | 12 | 23 | 8 | 22 | 10
- C M45x1.5 | 3 | 52 | 32 | 26.17 | 12 | 23 | 8 | 24 | 10
- C M52x1.5 | 3 | 60 | 38 | 29.56 | 12 | 23 | 8 | 27 | 10
Worked example: M22x1.5 Form A vs Form C
Both have a 27 mm collar, 2 mm thick, and a 19 mm hex 6 mm high. Form A has 9 mm of thread (17 mm long overall); Form C has 12 mm (20 mm long), for a deeper port.
Common problems
- Bottoms out before sealing: a Form C plug in a shallow port; use Form A.
- Wrong wrench: an ISO 272 hex (13, 16, 18, 21) was supplied instead of the DIN 475-1 size.
- Seal ring will not centre: from M18 the ring must sit in the recess d3; check the ring ID.
FAQ
What is DIN 7604?
A light hexagon head screw plug with collar and parallel metric fine thread, in Form A (short spigot) and Form C (long spigot).
How is it different from DIN 910?
DIN 910 is the heavy type with a taller head and G thread options; DIN 7604 has a lower head and a smaller hex on larger sizes.
Why does s get smaller from M16 to M18?
From M18 the standard switches to a flatter collar with a recess d3, and the hex drops to 17 mm. That is in the standard, not a typo.
Which wrench sizes are shown?
The DIN 475-1 widths, which are the default. DIN ISO 272 alternates (13, 16, 18, 21) must be ordered specifically.
Related guides and calculators
- Sealing rings (DIN 7603)
- Hex head screw plugs (DIN 910)
- Socket screw plugs (DIN 908)
- Wrench size chart
- All free machinist calculators
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