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Hex Weld Nut Dimensions (DIN 929, M3 to M16)

Guide · Updated October 28, 2026

DIN 929 covers hexagon weld nuts with three weld projections, sizes M3 to M16 coarse and M8 to M16 fine pitch, product grade A (DIN 929:2013). Values agree across the fasteners.eu DIN 929 table, the Aspen Fasteners DIN 929 spec sheet and the fasten.it DIN 929 page. Hex, corners, height and pilot diameter match in all three; projection heights h1 and h2 match in fasteners.eu and Aspen; hole size d3 matches in fasteners.eu and fasten.it. Not shown: projection width b and recommended sheet thickness, which we could confirm from only one source each. Check the current edition or your supplier for critical work.

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Step by step

Confirm the size: DIN 929 covers M3 to M16 coarse and fine pitch M8 to M16, product grade A. M14 is non-preferred.
Read the hex: s is the hex: M6 11 mm, M8 14 mm, M10 17 mm, M12 19 mm. These are larger than a normal hex nut.
Drill the sheet hole: The round pilot d2 locates in a hole d3 the same nominal size: M8 10.5 mm, M10 12.5 mm (H13).
Check the height: m is the nut height: M8 6.5 mm, M10 8 mm. Shorter than an ISO 4032 nut.
Know the projections: Three corner projections h1 tall melt down during resistance welding; h2 is the pilot step height.
Match the bolt: DIN 929 nuts are meant for bolts below property class 8.8. Use ISO 21670 for 8.8 and up.

DIN 929 hex weld nut dimensions (mm)

Columns: thread size (fine pitch in brackets), width across flats s (h13), width across corners e min, nut height m (h14), pilot diameter d2 (d11), projection height h1, pilot height h2, sheet hole d3 (H13).

Size | s | e min | m | d2 | h1 | h2 | d3 hole
M3 | 7.5 | 8.15 | 3 | 4.5 | 0.55 | 0.25 | 4.5
M4 | 9 | 9.83 | 3.5 | 6 | 0.65 | 0.35 | 6
M5 | 10 | 10.95 | 4 | 7 | 0.7 | 0.4 | 7
M6 | 11 | 12.02 | 5 | 8 | 0.75 | 0.4 | 8
M8 (M8 x 1) | 14 | 15.38 | 6.5 | 10.5 | 0.9 | 0.5 | 10.5
M10 (x 1.25, x 1) | 17 | 18.74 | 8 | 12.5 | 1.15 | 0.65 | 12.5
M12 (x 1.5, x 1.25) | 19 | 20.91 | 10 | 14.8 | 1.4 | 0.8 | 14.8
(M14) (M14 x 1.5) | 22 | 24.27 | 11 | 16.8 | 1.8 | 1 | 16.8
M16 (M16 x 1.5) | 24 | 26.51 | 13 | 18.8 | 1.8 | 1 | 18.8

Worked example: bolt length into an M8 weld nut

A 3 mm bracket bolted to 1.5 mm sheet with an M8 DIN 929 nut behind. Bracket + sheet + nut height m = 3 + 1.5 + 6.5 = 11 mm, so an M8 x 12 gives full engagement with 1 mm past the nut; an M8 x 16 sticks out 5 mm, fine only if nothing sits behind. Remember the pilot sits inside the sheet hole, so it adds no length.

Common problems

Weld spatter in the thread: mask or chase the thread after welding.
Hole too big: the nut can shift or weld off-center; use the supplier hole size.
Wrong wrench: the hex is a size up from a standard nut (M8 is 14 mm).
Coated nuts: zinc or oil can spoil projection welds; use plain nuts unless the process allows.

FAQ

What is a DIN 929 weld nut?

A hex nut with three weld projections on the corners and a short round pilot. The pilot drops into a hole in sheet metal and the projections are resistance welded.

What wrench fits an M8 DIN 929 weld nut?

14 mm, not 13 mm, because the weld nut hex is oversized. Once welded you normally turn the bolt.

What hole size for a DIN 929 weld nut?

The hole d3 matches the pilot: M6 8 mm, M8 10.5 mm, M10 12.5 mm, M12 14.8 mm (H13 tolerance).

How is DIN 929 different from ISO 21670?

DIN 929 has three corner projections and no flange, and suits bolts below class 8.8. ISO 21670 has a round flange and suits bolts up to 10.9.

Does DIN 929 include fine thread?

Yes: M8 x 1, M10 x 1.25, M10 x 1, M12 x 1.5, M12 x 1.25, M14 x 1.5 and M16 x 1.5 share the coarse dimensions.

What sheet thickness does DIN 929 suit?

Ranges vary by size and process; we only list values confirmed by several sources, so check the standard or your supplier.

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