DIN 6923 Serrated Flanged Hexagon Nuts — Black Oxide Steel (Class 8)

FULLERKREG DIN 6923 Class 8 serrated hexagon flange nuts with black oxide finish are manufactured from medium carbon steel 35K, quenched and tempered to achieve Class 8 mechanical properties, conforming to DIN 6923. The integrated serrated flange bearing surface distributes clamping load over a wider area and provides built-in vibration resistance — eliminating the need for a separate lock washer. Surface finish: black oxide (blackening) with oil post-treatment, providing a uniform matte black appearance and mild corrosion inhibition for indoor and controlled-environment applications. Thread: metric coarse (ISO 68-1). RoHS compliant.

Dimensional Data — DIN 6923 Serrated Flange Nut (Black Oxide, Class 8)

All dimensions in mm. Unit weight is approximate (calculated at steel density 7.85 g/cm³); actual weight may vary slightly by batch. Tolerances per DIN 6923. Black oxide coating adds negligible dimensional change (< 2.5 µm); no fit adjustment required.

Product Specifications

Material & Mechanical Properties — Medium Carbon Steel 35K (Class 8)

Chemical Composition — Medium Carbon Steel 35K

35K medium carbon steel is quenched and tempered to achieve Class 8 strength. The higher carbon content enables significantly greater tensile and proof load performance compared to low carbon steel grades.

Surface Treatment — Black Oxide (Blackening)

Black oxide is a conversion coating, not a plating. It does not add meaningful corrosion protection for outdoor or humid environments. For outdoor or marine use, consider zinc-plated (Zn Cr3) or stainless steel (A2 / A4) alternatives.

Black Oxide vs Zinc Plated — Surface Finish Comparison

Selection Guide — DIN 6923 Serrated Flange Nut (Class 8, Black Oxide)

Standard Reference

DIN 6923 specifies hexagon flange nuts with a serrated or plain bearing surface. The serrated variant provides mechanical locking through the teeth on the flange underside, which bite into the mating surface under torque — eliminating the need for a separate spring or toothed washer. Class 8 nuts are manufactured from medium carbon steel and must be quenched and tempered per DIN EN ISO 898-2. Black oxide (chemical blackening) is performed per applicable conversion coating standards. FULLERKREG manufactures to the current edition of DIN 6923 with full dimensional traceability.

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Why FULLERKREG

🏭 Direct Manufacturer — No middlemen. Factory-direct pricing with full production traceability.
📐 DIN Precision — Every batch produced and inspected to DIN 6923 dimensional standards.
🔩 Wide Size Range — M5 through M20 in stock; non-standard sizes available on request.
📦 Flexible MOQ & Packaging — Bulk bags, small boxes, or custom retail packaging to your specification.
🌍 Global Shipping — Direct export from China; experienced with Amazon FBA inbound, sea freight, and air freight.
✅ RoHS & Material Certs — Mill certificates, RoHS declarations, and inspection reports available on request.
🤝 OEM / Private Label — Custom marking, packaging, and labeling for wholesale partners.