DIN to ISO Cross-Reference - Metric Fastener Standards

DIN · ISO · EN · what the numbers mean and how they map

What it is

FIELD IDENTIFICATION

DIN numbers are German national standards; ISO numbers are international standards; EN numbers

are European. Many DIN fastener standards have been withdrawn and replaced by ISO equivalents,

but the old DIN numbers are still how parts are ordered.

DIN 933 = ISO 4017

Same part, two standard numbers

Common metric fastener standards

DIN

ISO equivalent

Product

DIN 931

ISO 4014

Hex head bolt, partly threaded

DIN 933

ISO 4017

Hex head screw, fully threaded

DIN 912

ISO 4762

Socket head cap screw

DIN 7991

ISO 10642

Socket countersunk (flat) head screw

(DIN 7380)

ISO 7380

Socket button head screw

DIN 7984

none

Socket cap screw, low head

DIN 913 / 914 / 915 / 916

ISO 4026 / 4027 / 4028 / 4029

Socket set screw: flat / cone / dog / cup point

DIN 934

ISO 4032

Hex nut (regular height)

DIN 439

ISO 4035

Thin (jam) nut

DIN 985

ISO 10511

Nylon-insert locknut, thin

DIN 982

ISO 7040

Nylon-insert locknut, regular

DIN 6923

ISO 4161

Hex flange nut

DIN 6921

ISO 4162

Hex flange bolt

DIN 125 A / B

ISO 7089 / ISO 7090

Flat washer / chamfered flat washer

DIN 9021

ISO 7093

Large (fender) washer

DIN 127

none (withdrawn)

Split spring lock washer

DIN 603

ISO 8677

Carriage bolt (cup square neck)

DIN 84 / 85

ISO 1207 / ISO 1580

Slotted cheese head / pan head screw

DIN 7985 / 965

ISO 7045 / ISO 7046

Phillips pan / countersunk machine screw

DIN 7981 / 7982

ISO 7049 / ISO 7050

Phillips pan / countersunk tapping screw

DIN 975 / 976

none

Threaded rod / stud

DIN 6914 / 6915 / 6916

EN 14399-4 / -6

Structural HV bolt / nut / washer

Key points

Across-flats sizes differ between DIN and ISO in four sizes: M10 (DIN 17 mm, ISO 16 mm), M12 (19 / 18), M14 (22 / 21) and M22 (32 / 34). This matters

for wrenches and for mixing bolts and nuts in a kit.

Strength is set separately by ISO 898-1 (bolt property class) and ISO 898-2 (nut class). A DIN or ISO product number tells you the shape; the class tells

you the strength.

"DIN EN ISO 4017" is the German adoption of ISO 4017, the same document.

Governing standards: DIN; ISO 4014:2022, 4017:2022, 4762:2004, 4032:2023 and related product standards; ISO 898-1:2013 / 898-2:2022; EN 14399. Editions shown are the latest

confirmed as of September 2026. The drawing and the governing standard always take precedence over this sheet.

torquing any fastener. Verify the current governing standard, project documents, OEM requirements, size, thread, coating and lot certification. To the fullest extent permitted by law, The Fastener App disclaims liability

arising from reliance on this reference.