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Nuts · GB/T 901 / DIN 939

GB/T 901 Thin Hex Nut Specification

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

GB/T 901 specifies the dimensions and tolerances for thin hex nut. The full dimensional table is reproduced below, followed by the DIN, ISO and ASME parts that match or supersede it.

Standard
GB/T 901
Product
Thin Hex Nut — GB/T 901 / DIN 939 (Series 094)
Governing standards
GB/T 901 / DIN 939

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

GB/T 901 Thin Hex Nut Specification reference image

GB/T 901 covers the dimensional requirements for thin hex nut. Reproduced below: the complete size table, and the companion and equivalent standards referenced when ordering to this document.

GB/T 901 — Scope

GB/T 901 is "Double end studs — Metal end 1.25 d". GB/T 901 is the Chinese national adoption of the same document.

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

GB/T 901 does not divide thin hex nut — gb/t 901 / din 939 (series 094) into product grades. Tolerances are given as limits on the individual dimensions in the table.

Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.

Dimensions Specified by GB/T 901

SizePitch (mm)Width across flats s (mm)Width across corners e (mm)Nut height m (mm)Reference standard
M30.55.56.011.8ISO 4035 / GB/T 6172
M40.77.07.662.2ISO 4035 / GB/T 6172
M50.88.08.792.7ISO 4035 / GB/T 6172
M61.010.011.053.2ISO 4035 / GB/T 6172
M81.2513.014.384.0ISO 4035 / GB/T 6172
M101.516.017.775.0ISO 4035 / GB/T 6172
M121.7518.020.036.0ISO 4035 / GB/T 6172
M142.021.023.367.0ISO 4035 / GB/T 6172
M162.024.026.758.0ISO 4035 / GB/T 6172
M182.527.030.149.0ISO 4035 / GB/T 6172
M202.530.033.5310.0ISO 4035 / GB/T 6172
M243.036.039.9812.0ISO 4035 / GB/T 6172
M303.546.050.8515.0ISO 4035 / GB/T 6172
M364.055.060.7918.0ISO 4035 / GB/T 6172

Equivalent Standards

Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Thin Hex Nut — GB/T 901 / DIN 939 (Series 094) page.

Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.

When to Specify GB/T 901

Choose GB/T 901 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for thin hex nut — gb/t 901 / din 939 (series 094).

Custom manufacturing · Made to drawing

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

Parts built to GB T 901 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 Thin Hex Nut — GB/T 901 / DIN 939 (Series 094) to GB/T 901 / DIN 939. 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)
1.8
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 901 / DIN 939)

SizePitch (mm)Width across flats s (mm)Width across corners e (mm)Nut height m (mm)Reference standard
M30.55.56.011.8ISO 4035 / GB/T 6172
M40.77.07.662.2ISO 4035 / GB/T 6172
M50.88.08.792.7ISO 4035 / GB/T 6172
M61.010.011.053.2ISO 4035 / GB/T 6172
M81.2513.014.384.0ISO 4035 / GB/T 6172
M101.516.017.775.0ISO 4035 / GB/T 6172
M121.7518.020.036.0ISO 4035 / GB/T 6172
M142.021.023.367.0ISO 4035 / GB/T 6172
M162.024.026.758.0ISO 4035 / GB/T 6172
M182.527.030.149.0ISO 4035 / GB/T 6172
M202.530.033.5310.0ISO 4035 / GB/T 6172
M243.036.039.9812.0ISO 4035 / GB/T 6172
M303.546.050.8515.0ISO 4035 / GB/T 6172
M364.055.060.7918.0ISO 4035 / GB/T 6172

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

The sectors that buy Thin Hex Nut to GB/T 901 / DIN 939, and the duty each one buys them for. Stocked from M3 to M36.

Industries that specify Thin Hex Nut

  • Machine building & OEM The clamping counter-face on studs and bolts throughout an assembly.
  • 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.

Typical applications

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

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.

Need help matching Thin Hex Nut to your application? Send the assembly, the load and the environment with your enquiry and we will specify the size, material and finish against them.

Video: GB/T 901 Thin Hex Nut Specification

Video: GB/T 901 Thin Hex Nut Specification

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

Which edition of GB/T 901 does this table follow?

The table reproduces the dimensions we supply thin hex nut — gb/t 901 / din 939 (series 094) 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.

What is GB/T 901?

GB/T 901 is "Double end studs — Metal end 1.25 d". GB/T 901 is the Chinese national adoption of the same document.

What does GB/T 901 specify for Thin Hex Nut — GB/T 901 / DIN 939 (Series 094)?

GB/T 901 specifies the dimensions and tolerances of thin hex nut — gb/t 901 / din 939 (series 094). Material and property class are governed by separate documents.

Does GB/T 901 specify the mechanical strength?

No. GB/T 901 controls only the geometry of thin hex nut — gb/t 901 / din 939 (series 094). The mechanical strength is set by ISO 898-1 (bolts, screws and studs) or ISO 898-2 (nuts), and the finish by separate documents.

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.