ISO 4032 dimensions
Hexagon regular nuts, style 1 — the ISO standard that replaced DIN 934.
The ISO standard. DIN 934 is the DIN number for the same part.
What ISO 4032 is
ISO 4032 supersedes DIN 934. The thread is the same and the nuts thread onto the same bolts. Whether the across-flats also differs between the two nut standards is not something this site holds checked data for, so it is not stated here — check the figure against whichever standard the part was actually made to.
ISO 4032 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 ISO 4032 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.
ISO 4032 against DIN 934
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 ISO 4032?
Hexagon regular nuts, style 1 — the ISO standard that replaced DIN 934. It is the ISO standard covering the same fastener as DIN 934.
Is ISO 4032 the same as DIN 934?
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 ISO 4032 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 ISO 4032 still current?
Yes. ISO 4032 is the current international standard; DIN 934 is the withdrawn German one that preceded it. Suppliers still sell and label parts by the DIN number because that is what customers ask for.
Other fastener standards
- 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
- DIN 912 — Hexagon socket head cap screws — the cylindrical head driven by a hex key
Every fastener standard here · Metric thread sizes · Tap drill sizes · Spanner sizes