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Knurled Nut Dimensions (DIN 6303, M5 to M10)
Guide · Updated October 28, 2026
DIN 6303 (2024 edition) covers knurled nuts M5 to M10, form A without and form B with pin hole. Values agree across the DIN 6303 table text, Elesa+Ganter, Halder and Ameco. Nominal sizes shown.
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Step by step
- Find the thread: Pick the row for your screw or stud, M5 to M10.
- Check the grip: dk is the knurled diameter, e.g. 24 mm for M6.
- Check the height: h is total height and k the knurled part, e.g. 14 and 10 mm for M6.
- Pick the form: Form A has no pin hole; form B has a cross hole for a pin of size dh, drilled through at assembly.
DIN 6303 knurled nut dimensions (mm)
Columns: thread d, pitch P, knurl diameter dk, collar diameter ds, height h, knurl height k, thread depth t, pin hole dh (form B).
- Size | P | dk | ds | h | k | t | dh
- M5 | 0.8 | 20 | 14 | 12 | 8 | 5 | 1.5
- M6 | 1 | 24 | 16 | 14 | 10 | 6 | 1.5
- M8 | 1.25 | 30 | 20 | 17 | 12 | 7 | 2
- M10 | 1.5 | 36 | 28 | 20 | 14 | 8 | 3
Worked example: M6 nut
An M6 DIN 6303 nut is 24 mm across the knurl, 14 mm tall with a 10 mm knurled band and a 16 mm collar. Form B takes a 1.5 mm pin.
Common problems
- Over-tightening with pliers: these nuts are for hand torque only.
- Stud too short: allow for thread depth t.
- Pin hole not drilled: form B is drilled through with the mating part at assembly.
FAQ
What is DIN 6303 used for?
Hand-tightened clamping on fixtures, guards and adjusters where no set preload is needed.
Is there an M12 DIN 6303 nut?
Not in the standard, which covers M5 to M10. Some suppliers sell an M12 version (dk 40, ds 32, h 24, k 16 mm per Ganter and Ameco), so it is left out of the chart.
What is form B?
Form B has a pin hole through the collar; after drilling through with the part, the hole should be H7 and takes an ISO 2338 dowel or similar pin.
Why does my nut look different?
Suppliers note knurl pitch and depth may differ from DIN; the main sizes in the chart still apply.
Related guides and calculators
- Wing screws (DIN 316)
- Low knurled thumb screws (DIN 653)
- Knurled thumb screws (DIN 464)
- Star knobs (DIN 6336)
- Tall knurled thumb nuts (DIN 466)
- Thin knurled thumb nuts (DIN 467)
- Spherical seat nuts (DIN 6330)
- Collar nuts (DIN 6331)
- All free machinist calculators
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