This tool provides dimensional data for metric hexagon bolts, nuts, and washers from M6 to M64, covering the most commonly used fastener sizes in structural steelwork, mechanical engineering, and general fabrication.
Select a bolt size from the panel to instantly display the side-view diagram and full set of dimensions for the bolt, nut, and washer. All diagrams update in real time and are labelled with the standard symbol for each dimension.
Bolt dimensions conform to ISO 4014 (hexagon head bolts, product grades A and B, partial thread). Head dimensions — width across flats s, width across corners e, and head height k — together with thread pitch p and thread length b are shown for each designation.
Nut dimensions conform to ISO 4032 (hexagon nuts, style 1, product grades A and B). The nut height m and width across flats s are given for the matching nut to each bolt size.
Washer dimensions conform to ISO 7089 (plain washers, normal series, product grade A). The inner diameter d₁, outer diameter d₂, and thickness h are shown.
Clearance hole diameters follow the medium fit series of ISO 273, which is the most commonly specified fit in structural connections.
HOW TO USE THIS TOOL
Use the sidebar to browse all available bolt sizes from M6 to M64, or type directly into the search field to jump to a specific designation — for example, type “M20” to go straight to the M20 data.
Three separate diagrams are shown for each bolt size: the bolt side view, the nut side view, and the washer side view. Each diagram is independently dimensioned with engineering-style arrows and labels. All dimensions are in millimetres.
DISCLAIMER
The information provided by this tool is intended for reference and preliminary design purposes only. While every effort has been made to ensure accuracy, Steel Explained makes no representations or warranties — express or implied — regarding the completeness, accuracy, or fitness for purpose of the data presented. Dimensional data is based on the nominal values published in the relevant ISO standards. Actual manufactured dimensions are subject to tolerances defined within those standards and may vary between suppliers. Users are strongly advised to verify all dimensions against current standards and supplier documentation before use in design, fabrication, or procurement. This tool does not constitute engineering advice. All design and specification work must be carried out or reviewed by a qualified engineer in accordance with the applicable codes and standards, including Eurocode 3 (EN 1993-1-8) for structural bolt connections and its relevant National Annexes. Steel Explained accepts no liability for any loss, damage, or consequence arising from reliance on the information provided by this tool.
STANDARDS REFERENCED
| Standard | Description |
|---|---|
| ISO 4014:2011 | Hexagon head bolts — Product grades A and B |
| ISO 4032:2012 | Hexagon nuts, style 1 — Product grades A and B |
| ISO 7089:2000 | Plain washers — Normal series — Product grade A |
| ISO 273:1979 | Fasteners — Clearance holes for bolts and screws |
| EN 1993-1-8 | Eurocode 3: Design of steel structures — Joints |
RELATED TOOLS
- European Steel Profile Dimensions Tool — Cross-sectional dimensions for IPE, HEA, HEB, HEM, UPN, L, SHS, RHS and CHS profiles per EN 10365:2017
- Steel Weight Estimator — Multi-item cut list with live weight totals for all standard EN profiles
