---
title: "Bolt Property Classes"
description: "Bolt Property Classes to ISO 898-1: full dimensional table. 10 catalogued sizes with materials and finishes. Technical drawing redraws to any row."
url: https://engineeringhardware.com/fastener/bolt-property-classes/
source: Engineering Hardware & Fasteners
---

# Bolt Property Classes

Engineering Reference · Bolt Property Classes

10 catalogued sizes, dimensioned to ISO 898-1. Pick any row and the technical drawing redraws to it.

Bolt Property Classes to ISO 898-1: the full dimensional table is reproduced below. 10 sizes are held in the table below, and the technical drawing redraws to whichever row you select.

- **Standard:** ISO 898-1
- **Catalogued sizes:** 10

Dimensions are nominal values from the governing standard. Confirm the tolerance class for your application before ordering.

![Bolt Property Classes technical product image](https://engineeringhardware.com/wp-content/uploads/2026/06/Hex-Bolts-—-ISO-4014-／-ISO-4017-Detail.webp)

Manufactured to ISO 898-1, Bolt Property Classes are engineering reference supplied by Engineering Hardware. The dimensional data, materials and selection notes are summarized here.

## About This Reference

This is an engineering reference table for bolt property classes based on ISO 898-1. Use it alongside our fastener catalog when selecting and specifying parts.

## Reference Data (ISO 898-1)

| Property class | Material | Tensile strength Rm (MPa) | Yield strength Re min (MPa) | Yield ratio | Diameter range | Application | Reference standard |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 4.6 | Low-carbon steel | 400 | 240 | 0.6 | M5 to M39 | General purpose | ISO 898-1 |
| 4.8 | Low-carbon steel (annealed) | 420 | 340 | 0.8 | M1.6~M16 | General purpose | ISO 898-1 |
| 5.6 | Low/medium-carbon steel | 500 | 300 | 0.6 | M5 to M39 | General purpose | ISO 898-1 |
| 5.8 | Low/medium-carbon steel | 520 | 420 | 0.8 | M1.6~M24 | General purpose | ISO 898-1 |
| 6.8 | Low/medium-carbon steel | 600 | 480 | 0.8 | M1.6~M24 | General purpose | ISO 898-1 |
| 8.8 | Medium-carbon steel (quenched & tempered) | 830 | 660 | 0.8 | Over M16 to M39 | High strength, most common | ISO 898-1 |
| 8.8 | Low-alloy steel (quenched & tempered) | 800 | 640 | 0.8 | M1.6 to M16 inclusive | High strength, most common | ISO 898-1 |
| 9.8 | Medium-carbon steel | 900 | 720 | 0.8 | M1.6~M16 | High strength | ISO 898-1 |
| 10.9 | Alloy steel (quenched & tempered) | 1040 | 940 | 0.9 | M5 to M39 | Ultra-high strength | ISO 898-1 |
| 12.9 | Alloy steel (quenched & tempered) | 1220 | 1100 | 0.9 | M1.6 to M39 | Very high strength, common for socket screws | ISO 898-1 |

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 does the Bolt Property Classes reference table cover?

Bolt Property Classes is an engineering reference table aligned with ISO 898-1. Use the values alongside our fastener catalog when selecting and specifying parts.

### How do I request a quotation?

Use the parametric drawing on this page to set the exact configuration (size, material, finish) and click "Request this configuration" — a specialist from Engineering Hardware will respond within one business day.