{"id":6828,"date":"2024-02-15T18:51:45","date_gmt":"2024-02-15T10:51:45","guid":{"rendered":"https:\/\/xzfastener.com\/?p=6828"},"modified":"2026-06-22T18:53:08","modified_gmt":"2026-06-22T10:53:08","slug":"metric-fastener-standards-din-iso-and-en-explained","status":"publish","type":"post","link":"https:\/\/xzfastener.com\/ru\/metric-fastener-standards-din-iso-and-en-explained\/","title":{"rendered":"Metric Fastener Standards: DIN, ISO and EN Explained"},"content":{"rendered":"

Metric fastener standards are easy to confuse. Many buyers send RFQs with \u201cDIN bolt,\u201d \u201cISO nut,\u201d or \u201cEN structural bolt,\u201d but these terms do not always control the same requirement.<\/p>\n\n\n\n

In purchasing, the standard number decides the product form, dimensions, thread, tolerance, mechanical grade, or assembly rule. If the wrong standard is used, the parts may look similar but fail during inspection or installation.<\/p>\n\n\n\n

What DIN, ISO and EN Mean<\/h2>\n\n\n\n

DIN Standards<\/h3>\n\n\n\n

DIN standards are German standards. They are still widely used in fastener drawings, old equipment manuals, warehouse systems, and distributor catalogs.<\/p>\n\n\n\n

Common examples include DIN hex bolts, DIN nuts, DIN washers, and DIN socket screws. Many older DIN items have ISO replacements, but buyers should not assume they are always identical.<\/p>\n\n\n\n

For regular metric items, start from standard fasteners<\/a> and confirm the exact standard before ordering.<\/p>\n\n\n\n

ISO Standards<\/h3>\n\n\n\n

ISO standards are international standards. They are widely used for global sourcing because they support common dimensions, thread systems, tolerances, mechanical properties, and inspection rules.<\/p>\n\n\n\n

For example, ISO standards may define bolt dimensions, washer dimensions, or mechanical properties such as 8.8, 10.9, and 12.9.<\/p>\n\n\n\n

EN Standards<\/h3>\n\n\n\n

EN standards are European standards. They are often important for construction, structural steelwork, and project compliance.<\/p>\n\n\n\n

For some structural fasteners, the buyer may need a bolting assembly standard, not only a bolt standard. That means bolt, nut, washer, marking, documents, and traceability must be checked together.<\/p>\n\n\n\n

Practical Comparison for Buyers<\/h2>\n\n\n\n
Standard Type<\/th>Main Use<\/th>Buyer Risk<\/th><\/tr><\/thead>
\u0414\u0418\u041d<\/td>Legacy drawings, replacement parts, distributor stock<\/td>Old DIN and ISO versions may differ<\/td><\/tr>
\u0418\u0421\u041e<\/td>International metric compatibility<\/td>Must still confirm grade, finish, and thread<\/td><\/tr>
EN<\/td>European project and structural requirements<\/td>May require assembly-level compliance<\/td><\/tr>
ISO 898-1<\/td>Bolt mechanical properties<\/td>Does not define coating or nut grade<\/td><\/tr>
EN 15048 \/ EN 14399<\/td>Structural bolting assemblies<\/td>Requires system-based checking<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

For load-bearing applications, review high-strength fasteners<\/a> before confirming grade and documents.<\/p>\n\n\n\n

Common Purchasing Mistakes<\/h2>\n\n\n\n

Buyers should avoid:<\/p>\n\n\n\n

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  1. Treating DIN and ISO numbers as fully interchangeable.<\/li>\n\n\n\n
  2. Ordering only by size without standard.<\/li>\n\n\n\n
  3. Using bolt standards for complete structural assemblies.<\/li>\n\n\n\n
  4. Ignoring nut and washer matching.<\/li>\n\n\n\n
  5. Forgetting coating thickness and thread fit.<\/li>\n\n\n\n
  6. Applying carbon steel standards to stainless steel products.<\/li>\n<\/ol>\n\n\n\n

    For corrosion-related projects, compare various coated fasteners<\/a> \u0438\u043b\u0438 stainless steel fasteners<\/a>.<\/p>\n\n\n\n

    RFQ Checklist<\/h2>\n\n\n\n

    A complete metric fastener RFQ should include:<\/p>\n\n\n\n