DIN / ISO / BS fastener equivalents and the sizes where they are not interchangeable

Equivalence between withdrawn DIN fastener standards and their current ISO and BS counterparts, and -- the part that is missing everywhere else -- the specific sizes at which the supposedly equivalent parts have different dimensions. Each record is one DIN standard with its ISO and BS counterpart and the publisher's interchangeability verdict, or one size at which a named dimension differs between the two standards. Answers 'is DIN 933 the same as ISO 4017', 'DIN 912 vs ISO 4762 are they interchangeable', 'my drawing says DIN 931 and my distributor only stocks ISO 4014', 'what replaced DIN 934', and 'DIN 125 ISO equivalent washer'. The headline mapping is easy and everyone publishes it; the exception detail is where free sources fail and contradict each other. Wurth, the German distributor that wrote the original catalogues, prints four sizes at which the width across flats changed between DIN 933 and ISO 4017 -- M10 17 mm becomes 16 mm, M12 19 becomes 18, M14 22 becomes 21, M22 32 becomes 34 -- meaning a different spanner. Monster Bolts lists the same pair as fully interchangeable. Both verdicts are published here, attributed, side by side, because the disagreement is the fact.

Records162

Sources3

Verified2026-08-05

Review by2029-08-04

LicenceFacts extracted from freely published distributor technical pages. Dimensions are facts, not copyrightable expression (US: Feist, 1991). ISO 4017 and the other ISO fastener documents were not purchased or opened; ISO's own terms restrict use of ISO content, and no ISO content is used here -- only dimensions as facts, quoted from distributors who published them. Three separate distributors, no bulk take from any one: the exception rows come from Wurth, the pair list from Monster Bolts, the BS column from TR Fastenings.

34 records where two or more sources state different values. Both sides are reproduced on the record page, each with its own source and quote.

The data

DIN standard	ISO standard	Part	Interchangeability verdict	BS standard	Size	Dimension that differs	DIN value	ISO value
DIN 1	ISO 2339	Cone Pins, untempered
DIN 125sources differ	ISO 7089, 7090	Washer, Plain	Fully interchangeable
DIN 126	ISO 7091	Product grade C washers - designed for use with Hexagon Head Bolts and Nut
DIN 127		Spring Lock Washers with square ends or tang ends		BS4464B
DIN 128		Curved and wave Spring Lock Washers
DIN 137		Spring Washers, curved or wave
DIN 1440	ISO 8738	Medium type washers for pins
DIN 1443	ISO 2340	Clevis Pins without head
DIN 1444	ISO 2341	Clevis Pins with head
DIN 1470	ISO 8739	Grooved Pins, full length parallel-grooved with pilot
DIN 1471	ISO 8744	Grooved Pins, full length taper-grooved
DIN 1472	ISO 8745	Grooved Pins, half length taper-grooved
DIN 1473	ISO 8740	Grooved Pins, full length parallel-grooved with chamfer
DIN 1474	ISO 8741	Grooved Pins, half length reverse-grooved
DIN 1475	ISO 8742	Grooved Pins, third length centre-grooved
DIN 1476	ISO 8746	Round Head Grooved Pins
DIN 1477	ISO 8747	Countersunk Head Grooved Pins
DIN 1481	ISO 8752	Spring-type Straight Pins (roll pins) - heavy type
DIN 1587		Hexagon Domed Cap Nuts
DIN 1816		Round Nut with set pin holes inside; ISO metric fine thread
DIN 315		Wing Nuts with rounded wings
DIN 316		Wing Screws with rounded wings
DIN 404		Slotted Capstan Screws
DIN 417sources differ	DIN EN 27435	Slotted Set Screw – Long Dog	Check spec
DIN 427sources differ	ISO 2342	Slotted Headless Screw with Shank	Fully interchangeable
DIN 428	ISO 4034	Hexagon Nuts, Grade C
DIN 433	ISO 7092	Washer, Plain Small	Fully interchangeable
DIN 433-1	ISO 7092	Product grade A washers - with a hardness up to 250 HV designed for use with cheese head screws
DIN 433-2	ISO 7092	Product grade A washers - with a hardness up to 300 HV designed for use with cheese head screws
DIN 438sources differ	DIN EN 27436	Slotted Set Screw – Cup	Check spec
DIN 439	ISO 4035, 4036	Hex Nut – Thin	Fully interchangeable
DIN 439-1	ISO 4036	Unchamfered Hexagon Thin Nuts - product grade B
DIN 439-2	ISO 4035	Chamfered Hexagon Thin Nuts - product grades A and B
DIN 440	ISO 7094	Washers for use in timber constructions
DIN 444		Eyebolts
DIN 462		Machine tools; internal tab washers for slotted round nuts for hook spanner according to DIN 1804
DIN 464		Knurled Thumb Screws, high type
DIN 466		Knurled Nuts, high type
DIN 467		Knurled Nuts, low type
DIN 471		Circlips (retaining rings) for shafts; normal type and heavy type
DIN 479		Square Head Bolts with short dog point
DIN 5406		Lock Washers and locking plates for use with rolling bearings
DIN 548		Round Nuts with set pin holes inside
DIN 551sources differ	ISO 4766	Slotted Set Screw – Flat	Check spec
DIN 553sources differ	ISO 7434	Slotted Set Screw – Cone	Check spec
DIN 555	ISO 4034	M5 to M100x6 Hexagon Nuts - product grade C
DIN 558sources differ	ISO 4018	Hex Head Bolts (FT), Metric Coarse	Fully interchangeable
DIN 580		Collar Eyebolts for lifting purposes
DIN 601sources differ	ISO 4016	Hex Head Bolts (PT), Metric Coarse	Fully interchangeable
DIN 603		Mushroom Head Square Neck Bolts
DIN 609		Hexagon Fits Bolts with long thread
DIN 6319		Spherical Washers and conical seats
DIN 6325	ISO 8734	Parallel Pins, hardened: tolerance zone m6
DIN 6340		Washers for clamping devices
DIN 653		Knurled Thumb Screws, low type
DIN 6797		Toothed Lock Washers
DIN 6798		Serrated Lock Washers
DIN 6799		Lock Washers (retaining washers) for shafts
DIN 6900	ISO 10644	Screw and Washer assemblies
DIN 6901	ISO 10510	Tapping Screw and Washer assemblies
DIN 6902	ISO 10673	Plain Washers for screw and washer assemblies
DIN 6903	ISO 10669	Plain Washers for tapping screw and washer assemblies
DIN 6912		Hexagon Socket Thin Head Cap Screws with pilot recess
DIN 6914	ISO 14399-4	High-strength Hexagon Head Bolts with large widths across flats for structural steel bolting
DIN 6916		Round Washers for high-strength structural steel bolting
DIN 6921sources differ	DIN EN 1665	Hex Head Bolts with Flange	Check spec
DIN 6922	ISO 1665	Hexagon Flange Bolts with reduced shank
DIN 6923sources differ	DIN EN 1661	Hex Nut with Flange	Check spec
DIN 6924	ISO 7040	Prevailing torque type Hexagon Nuts with non-metallic insert
DIN 6925	ISO 7042	Prevailing torque type all-metal Hexagon Nuts
DIN 6926sources differ	DIN EN 1663, 1666	Prevailing Torque Flange Nut	Check spec
DIN 6927sources differ	DIN EN 1664, 1667	Prevailing Torque Flange Nut	Check spec
DIN 7045		Pan Head Screws with type H or type Z cross recess - product grade A
DIN 7337	ISO 14589	Break mandrel Blind Rivets
DIN 7343	ISO 8750	Spiral Pins; normal type
DIN 7344	ISO 8748	Spiral Pins; heavy duty type
DIN 7346	ISO 13337	Spring-type Straight Pins; (roll pins) lightweight type
DIN 7349		Plain Washers for Bolts with heavy clamping sleeves
DIN 7500-1	ISO 7085	Thread rolling Screws for metric ISO thread - Part 1: Types, designation, requirements
DIN 7500-2		Thread rolling Screws for ISO metric thread; guideline values for hole diameters
DIN 7504		Self-drilling Screws with tapping screw thread - dimensions, requirements and testing
DIN 7513		Hexagon Head and slotted head thread cutting screws - dimensions, requirements and testing
DIN 7516		Cross recessed head thread cutting screws - dimensions, requirements and testing
DIN 7603		Ring Seals and Gaskets
DIN 7970	ISO 1478	Threads and thread ends for tapping screws (modified version of ISO 1478)
DIN 7971	ISO 1481	Slotted Pan Head Tapping Screws		BS4174
DIN 7972	ISO 1482	Slotted Countersunk Head Tapping Screws
DIN 7973	ISO 1483	Slotted Raised Countersunk Head Tapping Screws
DIN 7976	ISO 1479	Hex Head Self-Tapping Screws	Check spec
DIN 7977	ISO 8737	Taper Pins with thread ends and constant point lengths
DIN 7978	ISO 8736	Taper Pins with internal thread
DIN 7979	ISO 8733	Parallel Pins with internal thread
DIN 7980		Spring Lock Washers with square ends for cheese head screws		BS4464A
DIN 7981sources differ	ISO 7049	Cross Recessed Pan Head Tapping	Check spec
DIN 7982sources differ	ISO 7050	Cross Recessed Flat Head Tapping	Check spec
DIN 7983sources differ	ISO 7051	Cross Recessed Raised Countersunk Tapping	Check spec
DIN 7984		Hexagon Socket Thin Head Cap Screws
DIN 7985sources differ	ISO 7045	Cross Recessed Pan Head Screw	Fully interchangeable
DIN 7989-1		Washers for steel structures - product grade C
DIN 7989-2		Washers for steel structures - product grade A
DIN 7991sources differ	ISO 10642	Flat Head Socket Cap	Check spec
DIN 84sources differ	ISO 1207	Slotted Cheese Head Screw	Check spec
DIN 85	ISO 1580	Product grade A Slotted Pan Head Screws		BS4183
DIN 9021sources differ	ISO 7093	Washer, Plain Large	Fully interchangeable
DIN 908		Hexagon Socket Screw Plugs with parallel screw thread
DIN 910		Hexagon-duty hexagon Head Screw Plugs
DIN 911	ISO 2936	Hexagon Socket Screw Keys
DIN 912sources differ	ISO 4762	Socket Head Cap Screw, Coarse	Fully interchangeable
DIN 913sources differ	ISO 4026	Socket Set Screw – Flat Point	Fully interchangeable
DIN 914sources differ	ISO 4027	Socket Set Screw – Cone Point	Fully interchangeable
DIN 915sources differ	ISO 4028	Socket Set Screw – Dog Point	Fully interchangeable
DIN 916sources differ	ISO 4029	Socket Set Screw – Cup Point	Fully interchangeable
DIN 918-3		Overview of European standards for fasteners
DIN 921		Slotted Pan Head Screws with large head
DIN 923		Slotted Pan Head Screws with shoulder
DIN 929		Hexagon Weld Nuts
DIN 93		Tab Washers with long tab
DIN 930		Fine thread pitch partially Threaded Screws
DIN 931sources differ	ISO 4014	Sechskantschrauben mit Teilgewinde	dass sich bei den Abmessungen M10, M12, M14 und M22 die Schlüsselweiten geändert haben und somit andere Verschraubungswerkzeuge eingesetzt werden müssen
DIN 931-1	ISO 4014	M1,6 to M39 Hexagon Cap Screws partially threaded - product grades A and B		BS3692
DIN 931-2	ISO 4014	M42 to M160x6 Hexagon Cap Screws partially threaded - product grade B		BS3692
DIN 933sources differ	ISO 4017	Sechskantschrauben mit Vollgewinde	dass sich bei den Abmessungen M10, M12, M14 und M22 die Schlüsselweiten geändert haben und somit andere Verschraubungswerkzeuge eingesetzt werden müssen
DIN 934	ISO 4032	Hexagon Nuts with metric coarse and fine pitch thread - product classes A and B
DIN 935-1		Hexagon Slotted Nuts and Castle Nuts with metric coarse and fine pitch thread - product grades A and B
DIN 935-2		M42 to M160x6 Hexagon Head Bolts; product grade B
DIN 935-3		Hexagon Slotted Nuts with metric coarse pitch thread - product grade C
DIN 936		M8 to M52 and M8x1 to M52x3 hexagon thin nuts; product grades A and B		BS3692
DIN 937		Hexagon Thin Castle Nuts
DIN 938		Studs with a length of engagement equal to about 1 d
DIN 939		Studs with a length of engagement equal to about 1,25 d
DIN 94	ISO 1234	Split Pins
DIN 95		Slotted Raised Countersunk (oval) Head Wood Screws
DIN 96		Slotted Round Head Wood Screws
DIN 960sources differ	ISO 8765	Hex Head Bolts (PT), Metric Fine	Fully interchangeable
DIN 961sources differ	ISO 8676	Hex Head Bolts (FT), Metric Fine	Fully interchangeable
DIN 962		Designation system for fasteners
DIN 963sources differ	ISO 2009	Slotted Flat Head (Countersunk)	Check spec
DIN 964sources differ	ISO 2010	Slotted Raised Countersunk	Check spec
DIN 965sources differ	ISO 7046	Cross Recessed Flat Head	Check spec
DIN 966sources differ	ISO 7047	Cross Recessed Raised Countersunk	Check spec
DIN 970	ISO 4032	Hexagon Nuts; style 1; metric coarse thread, product grades A and B; ISO 4032 modified
DIN 971-1	ISO 8673	Style 1 Hexagon Nuts with metric fine pitch thread; property classes 6 and 8
DIN 971-2	ISO 8674	Style 2 Hexagon Nuts with metric fine pitch thread; property classes 10 and 12
DIN 972	ISO 4034	M5 to M39 Hexagon Nuts; style 1; product grade C (modified version of ISO 4034)
DIN 975		Threaded Rods
DIN 976-1		Metric thread Stud Bolts
DIN 976-2		Metric interference-fit thread Stud Bolts
DIN 977sources differ	ISO 21670	Hex Weld Nut with Flange	Check spec
DIN 979		Hexagon Thin Slotted Nuts and Castle Nuts with metric coarse and fine pitch thread - Product grades A and B
DIN 980	ISO 7042	All-metal prevailing torque type Hexagon Nuts
DIN 980, 6925	ISO 7042, 10513	Prevailing Torque All-Metal Nut	Check spec
DIN 981		Locknuts for use with rolling bearings
DIN 982	ISO 7040	Prevailing torque type Hexagon Nuts with non-metallic insert
DIN 982, 6924	ISO 7040, 10512	Prevailing Torque Nylon Insert Nut	Check spec
DIN 983		Retaining Rings with lugs for use on shafts (external circlips)
DIN 985sources differ	ISO 10511	Nylon Insert Lock Nut (thin)	Check spec
DIN 986		Prevailing torque type Hexagon Domed Cap Nuts with non-metallic insert
DIN 988		Shim Rings and supporting rings
DIN 933	ISO 4017	Sechskantschrauben mit Vollgewinde	andere Verschraubungswerkzeuge eingesetzt werden müssen		M10	Schlüsselweite	17 mm	16 mm
DIN 933	ISO 4017	Sechskantschrauben mit Vollgewinde	andere Verschraubungswerkzeuge eingesetzt werden müssen		M12	Schlüsselweite	19 mm	18 mm
DIN 933	ISO 4017	Sechskantschrauben mit Vollgewinde	andere Verschraubungswerkzeuge eingesetzt werden müssen		M14	Schlüsselweite	22 mm	21 mm
DIN 933	ISO 4017	Sechskantschrauben mit Vollgewinde	andere Verschraubungswerkzeuge eingesetzt werden müssen		M22	Schlüsselweite	32 mm	34 mm

Where this came from

Every record above links the page it was taken from and quotes the sentence that states it. These are the 3 sources this dataset was assembled from.

trfastenings.comhttps://www.trfastenings.com/knowledge-base/engineering-data/fastener-standards
monsterbolts.comhttps://monsterbolts.com/pages/common-din-numbers-for-metric-fasteners
wuerth.dehttps://www.wuerth.de/web/de/awkg/kompetenz/din_iso_normteile/din-933-931-iso-4014-4017-sechskantschrauben.php

Machine-readable

data.jsonThe whole dataset — every record with its source URL and source quote.
Open Knowledge Format bundleOne JSON object per line — every record's frontmatter and quoted span exactly as it is held here, in one fetch.
How this is made and checkedWhat "verified against source" does and does not mean.

162 records. Licence: Facts extracted from freely published distributor technical pages. Dimensions are facts, not copyrightable expression (US: Feist, 1991). ISO 4017 and the other ISO fastener documents were not purchased or opened; ISO's own terms restrict use of ISO content, and no ISO content is used here -- only dimensions as facts, quoted from distributors who published them. Three separate distributors, no bulk take from any one: the exception rows come from Wurth, the pair list from Monster Bolts, the BS column from TR Fastenings.. Last verified against source: 2026-08-05. Scheduled for re-check by: 2029-08-04.