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Nuts · GB/T 6170 / ISO 4032

ISO 4032 Hex Nut Specification

Dimensional table, tolerance classes and the DIN / ISO / ASME parts that supersede or match this standard.

ISO 4032 specifies the dimensions and tolerances for hex nut. The full dimensional table is reproduced below, followed by the DIN, ISO and ASME parts that match or supersede it.

Standard
ISO 4032
Product
Hex Nut — GB/T 6170 / ISO 4032 (Series 059)
Governing standards
GB/T 6170 / ISO 4032

Equivalence between national standards is dimensional, not always metallurgical. Check the property class separately when substituting.

ISO 4032 Hex Nut Specification reference image

ISO 4032 covers the dimensional requirements for hex nut. Reproduced below: the complete size table, and the companion and equivalent standards referenced when ordering to this document.

ISO 4032 — Scope

ISO 4032 is "Fasteners — Hexagon regular nuts (style 1) — Product grades A and B". It covers M1.6 to M64.

Material, property class, surface finish and packaging are governed by separate documents — ISO 898-1 and ISO 898-2 for mechanical property classes, ISO 4042 for electroplated finishes.

Tolerance & Product Grades

ISO 4032 defines product grades A and B. The grade sets how closely the finished part has to follow the nominal dimensions; it is not a strength rating.

Dimensions Specified by ISO 4032

SizePitch (mm)Width across flats s (mm)Width across corners e (mm)Nut height m (mm)Reference standard
M30.55.56.012.4ISO 4032 / GB/T 6170
M40.77.07.663.2ISO 4032 / GB/T 6170
M50.88.08.794.7ISO 4032 / GB/T 6170
M61.010.011.055.2ISO 4032 / GB/T 6170
M81.2513.014.386.8ISO 4032 / GB/T 6170
M101.516.017.778.4ISO 4032 / GB/T 6170
M121.7518.020.0310.8ISO 4032 / GB/T 6170
M142.021.023.3612.8ISO 4032 / GB/T 6170
M162.024.026.7514.8ISO 4032 / GB/T 6170
M182.527.030.1415.8ISO 4032 / GB/T 6170
M202.530.033.5318.0ISO 4032 / GB/T 6170
M243.036.039.9821.5ISO 4032 / GB/T 6170
M303.546.050.8525.6ISO 4032 / GB/T 6170
M364.055.060.7931.0ISO 4032 / GB/T 6170

Equivalent Standards

ISO 4032 hex nuts correspond to DIN 934 (style 1).

When to Specify ISO 4032

Choose ISO 4032 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for hex nut — gb/t 6170 / iso 4032 (series 059).

Custom manufacturing · Made to drawing

Need a nut to this standard in a non-standard size?

Parts built to ISO 4032 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down. Made by cold heading or tapping.

Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

Custom nut manufacturingSend a drawing

Technical Drawing

Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.

Dimensioned line drawing of M3 Hex Nut — GB/T 6170 / ISO 4032 (Series 059) to GB/T 6170 / ISO 4032. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.
Pitch (mm)
0.5
Width across flats s (mm)
5.5
Width across corners e (mm)
6.01
Nut height m (mm)
2.4
Opens a short step to confirm the exact specification before you enter contact details.

Request a Quote

Click “Request this configuration” under the drawing to confirm the exact specification, then add your contact details. You can also send the request without a specification — but only an accurate selection gets an accurate quote.

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Specification
Business Information

Dimensions & Specifications (GB/T 6170 / ISO 4032)

SizePitch (mm)Width across flats s (mm)Width across corners e (mm)Nut height m (mm)Reference standard
M30.55.56.012.4ISO 4032 / GB/T 6170
M40.77.07.663.2ISO 4032 / GB/T 6170
M50.88.08.794.7ISO 4032 / GB/T 6170
M61.010.011.055.2ISO 4032 / GB/T 6170
M81.2513.014.386.8ISO 4032 / GB/T 6170
M101.516.017.778.4ISO 4032 / GB/T 6170
M121.7518.020.0310.8ISO 4032 / GB/T 6170
M142.021.023.3612.8ISO 4032 / GB/T 6170
M162.024.026.7514.8ISO 4032 / GB/T 6170
M182.527.030.1415.8ISO 4032 / GB/T 6170
M202.530.033.5318.0ISO 4032 / GB/T 6170
M243.036.039.9821.5ISO 4032 / GB/T 6170
M303.546.050.8525.6ISO 4032 / GB/T 6170
M364.055.060.7931.0ISO 4032 / GB/T 6170

Materials & Grades

Select a material class to see the grades we supply it in. Each designation is listed with its ISO/EN, AISI/SAE, JIS and GB equivalents.

Stainless Steel38 Carbon Steel66 Alloy Steel41 Bearing Steel5 Spring Steel25 Aluminum and Aluminum Alloys21 Brass17 Bronze11 Copper8 Titanium and Titanium Alloys18 Nickel and Nickel Alloys22 Iron-Nickel and High-Temperature Alloys10 Tool Steel and Specialty Hardened Steel9 Structural and Construction Steel9

Stainless Steel

Austenitic Stainless Steel

  • A1 AISI 303 · SAE 303 · SUS303 · EN 1.4305 · X8CrNiS18-9
  • A2 AISI 304 · SAE 304 · SUS304 · EN 1.4301 · X5CrNi18-10 · 06Cr19Ni10
  • 304L AISI 304L · SUS304L · EN 1.4307 · X2CrNi18-9 · 022Cr19Ni10
  • 302 AISI 302 · SUS302 · EN 1.4310
  • 305 AISI 305 · SUS305 · EN 1.4303
  • A4 AISI 316 · SAE 316 · SUS316 · EN 1.4401 · X5CrNiMo17-12-2 · 06Cr17Ni12Mo2
  • 316L AISI 316L · SUS316L · EN 1.4404 · X2CrNiMo17-12-2 · 022Cr17Ni12Mo2
  • 321 AISI 321 · SUS321 · EN 1.4541 · X6CrNiTi18-10
  • 310 / 310S AISI 310 · AISI 310S · SUS310S · EN 1.4845
  • 302HQ AISI 302HQ
  • A3
  • A5
  • 347 AISI 347 · SUS347 · EN 1.4550 · X6CrNiNb18-10
  • 309 / 309S AISI 309 · AISI 309S · SUS309S

Martensitic Stainless Steel

  • AISI 410 SUS410 · EN 1.4006 · X12Cr13 · 12Cr13
  • AISI 420 SUS420J1 · SUS420J2 · EN 1.4021 · EN 1.4028 · 20Cr13 · 30Cr13
  • AISI 431 SUS431 · EN 1.4057 · X17CrNi16-2
  • C1
  • C3
  • C4
  • AISI 440A
  • AISI 440B
  • AISI 440C SUS440C · EN 1.4125

Ferritic Stainless Steel

  • AISI 430 SUS430 · EN 1.4016 · X6Cr17 · 10Cr17
  • F1
  • AISI 434
  • AISI 444

Precipitation-Hardening Stainless Steel

  • 17-4 PH AISI 630 · UNS S17400 · SUS630 · EN 1.4542 · X5CrNiCuNb16-4
  • 15-5 PH UNS S15500
  • 17-7 PH UNS S17700

Duplex and Super Duplex Stainless Steel

  • Duplex 2205 UNS S31803 · UNS S32205 · EN 1.4462
  • Super Duplex 2507 UNS S32750 · EN 1.4410
  • D2
  • D4
  • D6
  • D8
  • Lean Duplex 2101 UNS S32101
  • Super Duplex S32760 UNS S32760 · EN 1.4501

Carbon Steel

Low-Carbon Steel

  • SAE 1006
  • SAE 1008
  • SAE 1010
  • SAE 1018
  • SAE 1020
  • Q195
  • Q235
  • SAE 1012
  • SAE 1015
  • Q215
  • ML08
  • ML08Al
  • ML10
  • ML15
  • ML20
  • SWRCH6A
  • SWRCH8A
  • SWRCH10A
  • SWRCH12A
  • SWRCH15A
  • SWRCH18A

Medium-Carbon Steel

  • SAE 1035
  • SAE 1045
  • S45C
  • C45
  • SAE 1030
  • SAE 1040
  • SAE 1050
  • 30
  • 35
  • 40
  • 45
  • 50
  • S35C
  • S40C
  • S50C
  • C35
  • C40

High-Carbon Steel

  • SAE 1060
  • SAE 1070
  • 65Mn
  • SAE 1065
  • SAE 1075
  • SAE 1080
  • SAE 1085
  • SAE 1090
  • SAE 1095
  • 60
  • 65
  • 70
  • 75
  • 80
  • 85

Cold-Heading Steel

  • SWRCH22A
  • 10B21
  • SWRCH22K
  • SWRCH25K
  • SWRCH30K
  • SWRCH35K
  • SWRCH40K
  • ML20Mn
  • ML25
  • ML30
  • ML35
  • ML40
  • 15B25

Alloy Steel

Chromium Steel

  • 40Cr
  • 45Cr
  • AISI 5140
  • SAE 5140
  • AISI 5120
  • SAE 5120
  • SCr420
  • SCr440

Chromium-Molybdenum Steel

  • 35CrMo
  • 42CrMo
  • AISI 4140
  • SCM435
  • SCM440
  • 42CrMo4
  • 30CrMo
  • AISI 4130
  • SAE 4130
  • SAE 4140
  • AISI 4142
  • AISI 4145
  • SCM415
  • SCM420
  • SCM445
  • EN 1.7220
  • EN 1.7225
  • 25CrMo4
  • 34CrMo4

Nickel-Chromium-Molybdenum Steel

  • AISI 4340
  • SAE 4340
  • 40CrNiMo
  • SNCM439
  • EN 1.6511
  • 36CrNiMo4

Boron Alloy Steel

  • 10B22
  • 10B21
  • 15B21
  • 15B25
  • 20MnTiB
  • 20Mn2B
  • 35VB
  • 40MnB

Bearing Steel

Bearing Steel

  • GCr15
  • AISI 52100 SAE 52100 · UNS G52986
  • SUJ2
  • 100Cr6 EN 1.3505
  • GCr15SiMn

Spring Steel

Carbon Spring Steel

  • SAE 1065
  • SAE 1070
  • SAE 1075
  • SAE 1080
  • SAE 1095
  • 65
  • 70
  • 75
  • 80
  • 65Mn

Silicon-Manganese Spring Steel

  • 60Si2Mn
  • 60Si2MnA
  • SUP6
  • SUP7

Chromium-Vanadium Spring Steel

  • 50CrVA
  • SAE 6150
  • AISI 6150
  • SUP10

Stainless Spring Steel

  • AISI 301
  • SUS301
  • EN 1.4310
  • AISI 302
  • AISI 304
  • AISI 316
  • 17-7 PH

Aluminum and Aluminum Alloys

Commercially Pure Aluminum

  • 1050
  • 1060
  • 1070
  • 1100

2xxx Series Aluminum

  • 2024
  • 2011
  • 2014
  • 2017

5xxx Series Aluminum

  • 5052
  • 5083
  • 5754

6xxx Series Aluminum

  • 6061
  • 6061-T6
  • 6063
  • 6082
  • 6082-T6

7xxx Series Aluminum

  • 7075
  • 7075-T6
  • 7005
  • 7050
  • 7075-T73

Brass

Free-Cutting Brass

  • C36000
  • H62
  • HPb59-1
  • C3601
  • C3602
  • C3604
  • CuZn36Pb3
  • CuZn39Pb3
  • EN CW614N
  • EN CW617N
  • H65

Lead-Free Brass

  • C69300
  • C27450
  • CW510L
  • CW511L

Naval Brass

  • C46400
  • CuZn39Sn1

Bronze

Silicon Bronze

  • C65500
  • C65100
  • C65600

Phosphor Bronze

  • C51000
  • C52100
  • CuSn6
  • CuSn8

Aluminum Bronze

  • C95400
  • C95500
  • C63000
  • CuAl10Ni5Fe4

Copper

Copper

  • C11000
  • T2
  • C10100
  • C10200
  • C12200
  • T1
  • TU1
  • TU2

Titanium and Titanium Alloys

Commercially Pure Titanium

  • Grade 2
  • Grade 1
  • Grade 3
  • Grade 4
  • TA1
  • TA2
  • TA3

Alpha-Beta Titanium Alloys

  • Grade 5
  • Ti-6Al-4V
  • TC4
  • UNS R56400

Low-Interstitial Grade

  • Grade 23
  • Ti-6Al-4V ELI
  • UNS R56407

Other Titanium Fastener Alloys

  • Ti-6Al-6V-2Sn
  • Ti-6Al-2Sn-4Zr-2Mo
  • Beta-C titanium
  • Ti-10V-2Fe-3Al

Nickel and Nickel Alloys

Commercially Pure Nickel

  • Nickel 200
  • UNS N02200
  • Nickel 201
  • UNS N02201

Inconel Alloys

  • Inconel 625 UNS N06625
  • Inconel 718 UNS N07718
  • Inconel 600 UNS N06600
  • Inconel 601 UNS N06601
  • Inconel 686 UNS N06686
  • Inconel X-750 UNS N07750

Monel Alloys

  • Monel 400 UNS N04400
  • Monel K-500 UNS N05500

Hastelloy Alloys

  • Hastelloy C-276 UNS N10276
  • Hastelloy C-22 UNS N06022
  • Hastelloy B-2 UNS N10665
  • Hastelloy B-3 UNS N10675
  • Hastelloy X UNS N06002

Other Nickel Alloys

  • Alloy 20 UNS N08020
  • Alloy 625
  • Alloy 718
  • Alloy 825 UNS N08825
  • Alloy 925 UNS N09925

Iron-Nickel and High-Temperature Alloys

A286

  • A-286
  • UNS S66286
  • EN 1.4980

Invar

  • Invar 36
  • Alloy 36
  • UNS K93600
  • FeNi36

Alloy 42

  • Alloy 42
  • UNS K94100
  • FeNi42

Tool Steel and Specialty Hardened Steel

Tool Steel and Specialty Hardened Steel

  • AISI D2
  • AISI H13
  • SKD11
  • Cr12MoV
  • AISI O1
  • AISI A2
  • AISI S7
  • SKD61
  • 9CrSi

Structural and Construction Steel

Structural and Construction Steel

  • ASTM A36
  • Q235B
  • Q355B
  • S355JR
  • Q235C
  • Q355C
  • S235JR
  • S275JR
  • S355J2

Applications & Industries

Where Hex Nut are used, and what decides the specification in each case. Stocked from M3 to M36.

Industries that specify Hex Nut

  • Steel fabrication Bolted structural and frame connections.
  • Automotive & transport Vibration-prone joints where the locking type is specified on the drawing.
  • Maintenance & MRO Replacements matched to the existing bolt class, thread and finish.
  • Building services Threaded rod, channel and suspension assemblies.
  • Machine building & OEM The clamping counter-face on studs and bolts throughout an assembly.

Typical applications

  • completing a bolted joint on a stud, rod or bolt
  • locking an adjustment so it cannot drift
  • joints re-torqued at a service interval

Service conditions to specify against

Marine and coastal
Available in A4 (316) stainless for chloride exposure — coastal structures, pool halls, water treatment and deck hardware, where A2 will eventually pit.
High load
Supplied in ISO 898-1 property classes, so the joint can be designed to a stated proof load and tightened to a calculated torque rather than by feel.
Match the class
A nut below the bolt property class strips before the bolt reaches its own limit — pair class 8 nuts with 8.8 bolts, class 10 with 10.9.

Full application guide: where Hex Nut are used, how to specify them, and the cases they are wrong for

Video: ISO 4032 Hex Nut Specification

Iso 4032 Nuts

Third-party video, selected automatically for this topic. It is not produced by Engineering Hardware and is not a specification source — use the tables on this page for dimensional data.

Inside the plant

Manufactured in our own plant

This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.

  1. Wire rod feeding into a cold heading machine
    01

    Cold heading

    Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail.

    Head dimensions and under-head radius checked at set-up and per shift.

  2. Thread rolling machine producing bolt threads
    02

    Thread rolling

    Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch.

    Go / no-go ring gauges to ISO 965 tolerance class 6g.

  3. Baskets of bolts staged for heat treatment
    03

    Heat treatment

    Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it.

    Core hardness and tensile tested per lot to ISO 898-1.

  4. Zinc plated bolts in a treatment basket
    04

    Surface treatment

    Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list.

    Coating thickness and neutral salt spray hours to ISO 9227.

Frequently Asked Questions

What product grades does ISO 4032 define?

ISO 4032 defines product grades A and B. The grade sets how closely the finished part has to follow the nominal dimensions; it is not a strength rating.

Does ISO 4032 specify the mechanical strength?

No. ISO 4032 controls only the geometry of hex nut — gb/t 6170 / iso 4032 (series 059). The mechanical strength is set by ISO 898-1 (bolts, screws and studs) or ISO 898-2 (nuts), and the finish by separate documents.

Can I substitute ISO 4032 for the corresponding DIN standard on a drawing?

On modern drawings the ISO standard is the master reference; the older DIN equivalent is a cross-reference. For most dimensional purposes the parts are interchangeable, but check tolerance grades and the head height — these are the most common points of divergence.

Which edition of ISO 4032 does this table follow?

The table reproduces the dimensions we supply hex nut — gb/t 6170 / iso 4032 (series 059) to. We do not publish an edition year against it, so where the edition is contractually significant, cite the edition you require on the enquiry and we will confirm it against the table before quoting.

How do I request a quotation?

Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day.