DIN 934 dimensions
Hexagon nuts — the plain hex nut.
The DIN number. Superseded by ISO 4032, and still what everyone orders by.
What DIN 934 is
DIN 934 is the ordinary hexagon nut, the counterpart to a DIN 931 or DIN 933 bolt. It is the most-used nut standard in Europe and the one a supplier means by "hex nut" unless they say otherwise.
DIN 934 sizes
This section does not publish a nut dimension table. The figures are in a standard that costs money to read, and the free copies of it are supplier catalogues with scanned tables — which is exactly the kind of source that produces a confident wrong number. What is here instead is what can be checked: the thread, the pitch and the clearance hole, all of which a DIN 934 nut shares with the bolt it goes on.
The metric thread pages carry the pitch, tapping drill, clearance hole, hex key and spanner size for every size from M2 to M24, and the spanner figures there give both the DIN and the ISO across-flats where they differ.
DIN 934 against ISO 4032
The threads are identical and the two are fully interchangeable in the hole. The heads are not identical. At M10, M12, M14 — DIN specifies 17 mm, 19 mm, 22 mm across the flats where ISO specifies 16, 18, 21 mm. Everywhere else in this range the two agree exactly.
That difference is small and extremely annoying. An M10 bolt made to ISO 4032 takes a 16 mm spanner and one made to DIN 934 takes 17 mm. Both are M10, both thread into the same hole, and a socket set built for one will skip a size on the other. It is why metric sets sold today usually carry both 16 and 17.
Frequently asked questions
What is DIN 934?
Hexagon nuts — the plain hex nut. Its ISO equivalent is ISO 4032.
Is DIN 934 the same as ISO 4032?
The threads are the same and the two are interchangeable in the hole, but the heads differ at M10, M12, M14. M10, M12, M14 — DIN specifies 17 mm, 19 mm, 22 mm across the flats where ISO specifies 16, 18, 21 mm. Everywhere else the two agree.
What size hex key does an M10 DIN 934 take?
A nut is turned by a spanner, not a key. The across-flats depends on which standard the nut was made to, and the M10 thread page gives both figures.
Is DIN 934 still current?
Not formally — DIN 934 has been superseded by ISO 4032. It remains the number everyone uses: catalogues, drawings and purchase orders are still written in DIN numbers, and a supplier asked for DIN 934 will ship a part made to ISO 4032.
Other fastener standards
- ISO 4032 — Hexagon regular nuts, style 1 — the ISO standard that replaced DIN 934
- DIN 933 — Hexagon head bolts threaded all the way to the head — DIN’s own title calls these “set screws”, which today reads as a grub screw and is not what this is
- ISO 4017 — Hexagon head screws, fully threaded — the ISO standard that replaced DIN 933
- DIN 931 — Hexagon head bolts, partially threaded — a plain shank under the head
- ISO 4014 — Hexagon head bolts, partially threaded — the ISO standard that replaced DIN 931
Every fastener standard here · Metric thread sizes · Tap drill sizes · Spanner sizes