---
title: "ASME B18.2.2 Grade 5 UNF Fine-Thread Hex Nuts Specification"
description: "ASME B18.2.2 Grade 5 UNF Fine-Thread Hex Nuts: full dimensional table with tolerances. DIN, ISO and ASME equivalents listed side by side."
url: https://engineeringhardware.com/guide/standard/asme-b18-2-2-asme-b18-2-2-13-unc-hex-coupling-nut/
source: Engineering Hardware & Fasteners
---

# ASME B18.2.2 Grade 5 UNF Fine-Thread Hex Nuts Specification

Nuts · ASME B18.2.2 / ASTM A563 / ASME B1.1

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

ASME B18.2.2 specifies the dimensions and tolerances for grade 5 unf fine-thread hex nuts. The full dimensional table is reproduced below, followed by the DIN, ISO and ASME parts that match or supersede it.

- **Standard:** ASME B18.2.2
- **Product:** Grade 5 UNF Fine-Thread Hex Nuts
- **Governing standards:** ASME B18.2.2 / ASTM A563 / ASME B1.1

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

![ASME B18.2.2 Grade 5 UNF Fine-Thread Hex Nuts Specification reference image](https://engineeringhardware.com/wp-content/uploads/2026/09/Grade-5-UNF-Fine-Thread-Hex-Nuts.webp)

Grade 5 UNF Fine-Thread Hex Nuts manufactured to ASME B18.2.2 are dimensioned by the size table reproduced on this page. The standard fixes geometry and tolerances only; material and property class are assigned by separate documents, and surface finish by separate finish standards.

## ASME B18.2.2 — Scope

ASME B18.2.2 is "Nuts for general applications: machine screw nuts, hex, square, hex flange, and coupling nuts (inch series)". An inch-series 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

ASME B18.2.2 does not divide grade 5 unf fine-thread hex nuts 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 ASME B18.2.2

| Thread series | Material | Mating bolt grades | Finish options | Governing standards |
| --- | --- | --- | --- | --- |
| UNF fine | medium carbon steel | Grade 5 or Grade 8 hex bolts | zinc plating or black oxide | ASME B18.2.2 / ASTM A563 |
| UNF fine | medium carbon steel | Grade 5 hex bolts | zinc plating | ASME B1.1 thread form |

## Equivalent Standards

Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Grade 5 UNF Fine-Thread Hex Nuts page.

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

## When to Specify ASME B18.2.2

ASME B18.2.2 is the inch-based reference; for metric programs choose the ISO equivalent instead.

Custom manufacturing · Made to drawing

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

Parts built to ASME B18 2 2 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 UNF fine Grade 5 UNF Fine-Thread Hex Nuts to ASME B18.2.2 / ASTM A563 / ASME B1.1. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.

- **Material:** medium carbon steel
- **Mating bolt grades:** Grade 5 or Grade 8 hex bolts
- **Finish options:** zinc plating or black oxide
- **Governing standards:** ASME B18.2.2 / ASTM A563

## Dimensions & Specifications (ASME B18.2.2 / ASTM A563 / ASME B1.1)

| Thread series | Material | Mating bolt grades | Finish options | Governing standards |
| --- | --- | --- | --- | --- |
| UNF fine | medium carbon steel | Grade 5 or Grade 8 hex bolts | zinc plating or black oxide | ASME B18.2.2 / ASTM A563 |
| UNF fine | medium carbon steel | Grade 5 hex bolts | zinc plating | ASME B1.1 thread form |

Product catalog

## Related Inch Hex Nuts products

[![Black Galvanized High Strength Unc Inch Carbon Steel Self Locking Thin Nut](https://img.engineeringhardware.com/Black-Galvanized-High-Strength-Unc-Inch-Carbon-Steel-Self-Locking-Thin-Nut.webp)](https://engineeringhardware.com/product/black-galvanized-high-strength-unc-inch-carbon-steel-self-locking-thin-nut/)

Hex & Other Standard Nuts

### [Black Galvanized High Strength Unc Inch Carbon Steel Self Locking Thin Nut](https://engineeringhardware.com/product/black-galvanized-high-strength-unc-inch-carbon-steel-self-locking-thin-nut/)

Thin Nut · DIN, ANSI, GB, JIS, GOST, BSW, ISO

**US$0.0516 – 0.0672**MOQ 20,000 pieces

[![High-Performance Uns R60704 Zirconium Nuts for Chemical Industry](https://img.engineeringhardware.com/High-Performance-Uns-R60704-Zirconium-Nuts-for-Chemical-Industry.webp)](https://engineeringhardware.com/product/high-performance-uns-r60704-zirconium-nuts-for-chemical-industry/)

Hex & Other Standard Nuts

### [High-Performance Uns R60704 Zirconium Nuts for Chemical Industry](https://engineeringhardware.com/product/high-performance-uns-r60704-zirconium-nuts-for-chemical-industry/)

ASTM B550, ASTM B551, GB/T21183 - 2007 · Zirconium

**US$0.60 – 0.96**MOQ 100 pieces

[![Customized Carbon Steel Alloy Steel Welding Nuts for Special Machinery](https://img.engineeringhardware.com/Customized-Carbon-Steel-Alloy-Steel-Welding-Nuts-for-Special-Machinery.webp)](https://engineeringhardware.com/product/customized-carbon-steel-alloy-steel-welding-nuts-for-special-machinery/)

Hex & Other Standard Nuts

### [Customized Carbon Steel Alloy Steel Welding Nuts for Special Machinery](https://engineeringhardware.com/product/customized-carbon-steel-alloy-steel-welding-nuts-for-special-machinery/)

Hexagon Head · GB

**US$0.0168**MOQ 1 piece

[![DIN6923 Steel Stainless Steel Class 8 Metric M12-1.5 Galvanized Serrated Flange Hex Nut](https://img.engineeringhardware.com/DIN6923-Steel-Stainless-Steel-Class-8-Metric-M12-1-5-Galvanized-Serrated-Flange-Hex-Nut.webp)](https://engineeringhardware.com/product/din6923-steel-stainless-steel-class-8-metric-m12-1-5-galvanized-serrated-flange-hex/)

Hex & Other Standard Nuts

### [DIN6923 Steel Stainless Steel Class 8 Metric M12-1.5 Galvanized Serrated Flange Hex Nut](https://engineeringhardware.com/product/din6923-steel-stainless-steel-class-8-metric-m12-1-5-galvanized-serrated-flange-hex/)

Hexagon Head With Flange · DIN

**US$0.012 – 0.30**MOQ 1,000 pieces

[![Malaxy Quality Assurance Black Zinc Plated Hex Nut DIN985 Hex Nut](https://img.engineeringhardware.com/Malaxy-Quality-Assurance-Black-Zinc-Plated-Hex-Nut-DIN985-Hex-Nut.webp)](https://engineeringhardware.com/product/malaxy-quality-assurance-black-zinc-plated-hex-nut-din985-hex-nut/)

Hex & Other Standard Nuts

### [Malaxy Quality Assurance Black Zinc Plated Hex Nut DIN985 Hex Nut](https://engineeringhardware.com/product/malaxy-quality-assurance-black-zinc-plated-hex-nut-din985-hex-nut/)

Hexagon Head · DIN, ANSI, GB, JIS, GOST, BSW

**US$1,560 – 1,920**MOQ 1,000 tons

[![High Precision Bearing Lock Sleeve Adapter Sleeve H3132 H3134 H3136 H3138 Adapter Sleeve with Locking Nut and Locking Device](https://img.engineeringhardware.com/High-Precision-Bearing-Lock-Sleeve-Adapter-Sleeve-H3132-H3134-H3136-H3138-Adapter-Sleeve-with-Locking-Nut-and-Locking-Device.webp)](https://engineeringhardware.com/product/high-precision-bearing-lock-sleeve-adapter-sleeve-h3132-h3134-h3136-h3138-adapter/)

Hex & Other Standard Nuts

### [High Precision Bearing Lock Sleeve Adapter Sleeve H3132 H3134 H3136 H3138 Adapter Sleeve with Locking Nut and Locking Device](https://engineeringhardware.com/product/high-precision-bearing-lock-sleeve-adapter-sleeve-h3132-h3134-h3136-h3138-adapter/)

Bearing Roller · Chrome Steel

**US$0.60 – 15.60**MOQ 20 pieces

[View all Hex & Other Standard Nuts →](https://engineeringhardware.com/fastener-products/nuts/hex-other-standard-nuts/) [Full product catalog](https://engineeringhardware.com/products/)

## 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

What Grade 5 UNF Fine-Thread Hex Nuts are specified for, industry by industry.

### Industries that specify Grade 5 UNF Fine-Thread Hex Nuts

- **Industrial machinery:** Higher thread engagement per unit of length.
- **Maintenance:** Zinc or black oxide to match the existing assembly.
- **Automotive assembly:** Fine threads give a closer preload adjustment.
- **Agricultural equipment:** Mates with Grade 5 and Grade 8 American hex bolts.
- **Building services:** Threaded rod, channel and suspension assemblies.
- **Machine building & OEM:** The clamping counter-face on studs and bolts throughout an assembly.

### Typical applications

- selecting the finish to match the mating hardware
- confirming UNF rather than UNC before ordering
- pairing with a Grade 5 or Grade 8 inch bolt
- using the finer pitch where preload must be set closely
- 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.

### Where to use something else

- Do not mix UNC and UNF of the same nominal size on one machine; the two look alike and will cross-thread.

[Full application guide: where Grade 5 UNF Fine-Thread Hex Nuts are used, how to specify them, and the cases they are wrong for](https://engineeringhardware.com/applications/grade-5-unf-fine-thread-hex-nuts/)

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

### Does ASME B18.2.2 specify the mechanical strength?

No. ASME B18.2.2 controls only the geometry of grade 5 unf fine-thread hex nuts. 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 ASME B18.2.2 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 ASME B18.2.2 does this table follow?

The table reproduces the dimensions we supply grade 5 unf fine-thread hex nuts 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 ASME B18.2.2?

ASME B18.2.2 is "Nuts for general applications: machine screw nuts, hex, square, hex flange, and coupling nuts (inch series)". An inch-series document.

### 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 Grade 5 UNF Fine-Thread Hex Nuts page](https://engineeringhardware.com/fastener/grade-5-unf-fine-thread-hex-nuts/)

### More Grade 5 UNF Fine-Thread Hex Nuts Guides