DIN to ISO cross-reference.

Most DIN fastener standards have been replaced by ISO equivalents: DIN 933 by ISO 4017, DIN 934 by ISO 4032, DIN 125 by ISO 7089. The parts are interchangeable in use, but some spanner sizes and nut heights changed, which matters for tooling and for mixed stock.

Reviewed 11 Nov 2026 · Based on ISO 4014:2022, ISO 4017:2022, ISO 4032:2023; DIN 931, DIN 933, DIN 934 (withdrawn, still widely ordered); ISO 7089:2000 Plain washers — Normal series; ASME B18.2.1, B18.2.2, B18.3, B18.22.1 · Report an error

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Equivalent standards
ProductDINISOInch (ASME / ASTM)What changed
Hexagon head bolt, part threadDIN 931ISO 4014ASME B18.2.1 (heavy hex / hex bolt)Across flats changed for M10, M12, M14, M22 (see table)
Hexagon head screw, full threadDIN 933ISO 4017ASME B18.2.1 (hex cap screw)Across flats changed for M10, M12, M14, M22
Hexagon nutDIN 934ISO 4032 (style 1)ASME B18.2.2Across flats as above; ISO nuts are taller (m ≈ 0.84–0.9 d vs 0.8 d)
Hexagon nut, fine threadDIN 934 (fine)ISO 8673ASME B18.2.2As for ISO 4032
Socket head cap screwDIN 912ISO 4762ASME B18.3Dimensions essentially unchanged
Plain washerDIN 125-AISO 7089 (ISO 7090 chamfered)ASME B18.22.1 (plain washers)Nominal dimensions largely aligned
Prevailing-torque nut (nylon insert)DIN 982 / DIN 985ISO 7040 / ISO 10511ASME B18.16.6Heights and across flats follow the ISO hex changes
Threaded rodDIN 975 / DIN 976-1No ISO product standardASTM A193 B7, A307, F1554 (material specs)Order inch rod by material spec; metric rod by DIN with property class
Source: ISO 4014, 4017, 4032, 8673, 4762, 7089, 7090, 7040, 10511; DIN 931, 933, 934, 912, 125, 982, 985, 975, 976-1; ASME B18 series.
Across-flats sizes that changed from DIN to ISO (mm)
SizeDIN 931 / 933 / 934ISO 4014 / 4017 / 4032
M101716
M121918
M142221
M223234
Source: DIN 933 / 934 and ISO 4017 / 4032.
Nut height, ISO 4032 vs DIN 934 (mm)
SizeISO 4032 mDIN 934 mSpanner ISOSpanner DIN
M32.42.45.55.5
M43.23.277
M54.7488
M65.251010
M86.86.51313
M108.481617
M1210.8101819
M1412.8112122
M1614.8132424
M2018163030
M2219.4183432
M2421.5193636
M2723.8224141
M3025.6244646
M3631295555
Source: ISO 4032 and DIN 934 nominal dimensions. ISO nuts are taller so that, under overload, the bolt breaks before the nut thread strips.

Reference values, not a design.

Values are the nominal figures of the cited standards, or calculated from them where marked. The governing standard and your drawing always take precedence.

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Questions buyers ask.

Is DIN 933 the same as ISO 4017?

ISO 4017 replaced DIN 933 for fully threaded hexagon head screws. They are interchangeable in use, but the across-flats size differs for M10 (17 vs 16 mm), M12 (19 vs 18 mm), M14 (22 vs 21 mm) and M22 (32 vs 34 mm).

Is DIN 934 the same as ISO 4032?

ISO 4032 replaced DIN 934 for hexagon nuts. Besides the same across-flats changes, ISO 4032 nuts are taller (for example 10.8 mm against 10 mm at M12), so check clearances if you mix stock.

What replaced DIN 125?

ISO 7089 (plain washers, normal series) and ISO 7090 (chamfered) replaced DIN 125-A and 125-B. Nominal dimensions are largely the same.

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