--- title: "ISO 4032 Hex Nut Specification" description: "ISO 4032 Hex Nut: full dimensional table with tolerances. DIN, ISO and ASME equivalents listed side by side. Head, thread and length ranges in one chart." url: https://engineeringhardware.com/guide/standard/iso-4032-hex-nuts/ source: Engineering Hardware & Fasteners --- # ISO 4032 Hex Nut Specification Nuts · GB/T 6170 / ISO 4032 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 061) - **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](https://engineeringhardware.com/wp-content/uploads/2026/06/Hex-Nuts-—-ISO-4032-／-ISO-4033-Detail.webp) 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 | Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Nut height m (mm) | Reference standard | | --- | --- | --- | --- | --- | --- | | M3 | 0.5 | 5.5 | 6.01 | 2.4 | ISO 4032 / GB/T 6170 | | M4 | 0.7 | 7.0 | 7.66 | 3.2 | ISO 4032 / GB/T 6170 | | M5 | 0.8 | 8.0 | 8.79 | 4.7 | ISO 4032 / GB/T 6170 | | M6 | 1.0 | 10.0 | 11.05 | 5.2 | ISO 4032 / GB/T 6170 | | M8 | 1.25 | 13.0 | 14.38 | 6.8 | ISO 4032 / GB/T 6170 | | M10 | 1.5 | 16.0 | 17.77 | 8.4 | ISO 4032 / GB/T 6170 | | M12 | 1.75 | 18.0 | 20.03 | 10.8 | ISO 4032 / GB/T 6170 | | M14 | 2.0 | 21.0 | 23.36 | 12.8 | ISO 4032 / GB/T 6170 | | M16 | 2.0 | 24.0 | 26.75 | 14.8 | ISO 4032 / GB/T 6170 | | M18 | 2.5 | 27.0 | 30.14 | 15.8 | ISO 4032 / GB/T 6170 | | M20 | 2.5 | 30.0 | 33.53 | 18.0 | ISO 4032 / GB/T 6170 | | M24 | 3.0 | 36.0 | 39.98 | 21.5 | ISO 4032 / GB/T 6170 | | M30 | 3.5 | 46.0 | 50.85 | 25.6 | ISO 4032 / GB/T 6170 | | M36 | 4.0 | 55.0 | 60.79 | 31.0 | ISO 4032 / GB/T 6170 | ## Companion Standards ISO 4032 controls only the geometry of hex nut — gb/t 6170 / iso 4032 (series 061). The mechanical strength is set by ISO 898-1 (bolts, screws and studs) or ISO 898-2 (nuts); the surface finish is governed by separate finish standards such as ISO 4042 for electroplating. For corrosion testing, the relevant document is ISO 9227 (neutral salt spray). ## 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 061). 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 manufacturing](https://engineeringhardware.com/custom/nuts/)[Send a drawing](https://engineeringhardware.com/custom/nuts/#rfq) ## Technical Drawing Dimensioned line drawing of M3 Hex Nut — GB/T 6170 / ISO 4032 (Series 061) 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 ## Dimensions & Specifications (GB/T 6170 / ISO 4032) | Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Nut height m (mm) | Reference standard | | --- | --- | --- | --- | --- | --- | | M3 | 0.5 | 5.5 | 6.01 | 2.4 | ISO 4032 / GB/T 6170 | | M4 | 0.7 | 7.0 | 7.66 | 3.2 | ISO 4032 / GB/T 6170 | | M5 | 0.8 | 8.0 | 8.79 | 4.7 | ISO 4032 / GB/T 6170 | | M6 | 1.0 | 10.0 | 11.05 | 5.2 | ISO 4032 / GB/T 6170 | | M8 | 1.25 | 13.0 | 14.38 | 6.8 | ISO 4032 / GB/T 6170 | | M10 | 1.5 | 16.0 | 17.77 | 8.4 | ISO 4032 / GB/T 6170 | | M12 | 1.75 | 18.0 | 20.03 | 10.8 | ISO 4032 / GB/T 6170 | | M14 | 2.0 | 21.0 | 23.36 | 12.8 | ISO 4032 / GB/T 6170 | | M16 | 2.0 | 24.0 | 26.75 | 14.8 | ISO 4032 / GB/T 6170 | | M18 | 2.5 | 27.0 | 30.14 | 15.8 | ISO 4032 / GB/T 6170 | | M20 | 2.5 | 30.0 | 33.53 | 18.0 | ISO 4032 / GB/T 6170 | | M24 | 3.0 | 36.0 | 39.98 | 21.5 | ISO 4032 / GB/T 6170 | | M30 | 3.5 | 46.0 | 50.85 | 25.6 | ISO 4032 / GB/T 6170 | | M36 | 4.0 | 55.0 | 60.79 | 31.0 | ISO 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 Hex Nut are bought for a small number of well-defined jobs. These are the ones we ship them for. Stocked from M3 to M36. ### Industries that specify Hex Nut - **Building services:** Threaded rod, channel and suspension assemblies. - **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. ### Typical applications - joints re-torqued at a service interval - completing a bolted joint on a stud, rod or bolt - locking an adjustment so it cannot drift ### 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 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. 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](https://engineeringhardware.com/wp-content/uploads/2026/08/09-wire-rod-feed-cold-heading-machine.webp) 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](https://engineeringhardware.com/wp-content/uploads/2026/08/03-thread-rolling-machine-bolt-production.webp) 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](https://engineeringhardware.com/wp-content/uploads/2026/08/05-heat-treatment-baskets-black-bolts.webp) 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](https://engineeringhardware.com/wp-content/uploads/2026/08/23-zinc-plated-bolts-treatment-basket.webp) 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 is the equivalent of ISO 4032 in DIN or ASME? ISO 4032 hex nuts correspond to DIN 934 (style 1). ### 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 061). 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. ### 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. ## Related Pages [View the full Hex Nut — GB/T 6170 / ISO 4032 (Series 061) page](https://engineeringhardware.com/fastener/cad-svg-061-hexnut/) ### More Hex Nut — GB/T 6170 / ISO 4032 (Series 061) Guides