Home » DIN 6921 Hex Flange Bolt Grade 10.9 ZINC YELLOW

DIN 6921 Hex Flange Bolt Grade 10.9 ZINC YELLOW

DIN 6921 Hex Flange Bolt — Grade 10.9 | Zinc Yellow | FULLERKREG

FULLERKREG DIN 6921 Hex Flange Bolts are engineered for high-strength fastening in demanding automotive and new energy vehicle (NEV) applications. Manufactured at our Wuhu facility — located in the heart of China's automotive industry, home to Chery Automobile — these bolts meet the rigorous dimensional and mechanical requirements of DIN 6921 and DIN EN ISO 898-1.

Product Overview

  • Standard: DIN 6921
  • Type: Hexagon Flange Bolt (with or without serration)
  • Material: Alloy Steel 10B21
  • Property Class / Grade: 10.9 (per DIN EN ISO 898-1)
  • Surface Treatment: Zinc Yellow (Zinc Flake / Dacromet-equivalent yellow passivation)
  • Thread: Metric coarse thread (ISO 68-1)
  • Brand: FULLERKREG
  • Manufacturing Origin: Wuhu, Anhui, China

Two Flange Head Types Available

① Non-Serrated Flange (Smooth Flange)

The standard DIN 6921 configuration. The flange underhead bearing surface is smooth, providing a large, even clamping area that distributes load across the joint. Ideal for applications where the mating surface must not be marred or where vibration resistance is achieved through other means (e.g., thread-locking compounds or prevailing torque nuts).

  • Smooth flange underside
  • Larger bearing area reduces surface pressure
  • Suitable for softer substrates and painted surfaces
  • Preferred in body panel and bracket assemblies

② Serrated Flange (Toothed Flange)

Features radial serrations on the flange underside that bite into the mating surface upon tightening, providing superior vibration and loosening resistance without additional locking elements. Widely used in powertrain, chassis, and battery pack assemblies where dynamic loads and vibration are constant.

  • Integral serrated locking feature
  • Excellent resistance to vibration-induced loosening
  • Eliminates need for separate lock washers
  • Preferred in drivetrain, motor mounts, and EV battery enclosures

Material & Mechanical Properties

Property Specification Standard Reference
Material Alloy Steel 10B21 (boron steel) DIN EN ISO 898-1
Property Class 10.9 DIN EN ISO 898-1
Nominal Tensile Strength (Rm) ≥ 1040 MPa DIN EN ISO 898-1
Proof Load Stress (Sp) 940 MPa DIN EN ISO 898-1
Yield Strength (Rp0.2) ≥ 940 MPa DIN EN ISO 898-1
Hardness (Vickers) 320 – 380 HV DIN EN ISO 898-1
Core Hardness (Rockwell) 33 – 39 HRC DIN EN ISO 898-1
Elongation after fracture ≥ 9% DIN EN ISO 898-1
Surface Treatment Zinc Yellow (yellow chromate / zinc flake) DIN 267-11
Corrosion Resistance ≥ 720 hours neutral salt spray (NSS) DIN 267-11 / ISO 9227

Dimensional Reference — DIN 6921 Key Parameters

Thread Size Pitch (mm) Width Across Flats s (mm) Flange Diameter dc (mm) Head Height k (mm)
M5 0.8 8 14.2 3.5
M6 1.0 10 17.0 4.0
M8 1.25 13 22.0 5.5
M10 1.5 15 / 16 27.0 6.5
M12 1.75 18 32.0 8.0
M14 2.0 21 37.0 9.0
M16 2.0 24 43.0 10.0
M20 2.5 30 54.0 12.5

Full dimensional tables per DIN 6921. Custom lengths and thread pitches available upon request.

Surface Treatment: Zinc Yellow

The Zinc Yellow finish applied to FULLERKREG DIN 6921 bolts provides a dual function: corrosion protection and visual identification. Compliant with DIN 267-11 requirements for electroplated and zinc-flake coatings on fasteners.

  • Color: Distinctive yellow / golden iridescent appearance
  • Corrosion Protection: ≥ 720 hours neutral salt spray (NSS) to first red rust
  • Coating Type: Zinc flake (Geomet / Dacromet equivalent) or zinc electroplate with yellow chromate passivation
  • RoHS Compliant: Trivalent chromate process available (Cr³⁺, no hexavalent chromium)
  • Hydrogen Embrittlement Risk: Minimized through controlled baking process post-plating (per DIN EN ISO 4042)
  • Identification: Yellow color serves as a quick visual indicator for Grade 10.9 zinc-coated fasteners in assembly lines

Primary Application Sectors

🔋 New Energy Vehicles (NEV / EV)

FULLERKREG DIN 6921 Grade 10.9 Zinc Yellow bolts are widely specified in electric vehicle platforms for:

  • Battery pack enclosure and module assembly
  • Electric motor mounting and drive unit housings
  • High-voltage connector brackets and busbar fixings
  • Thermal management system (TMS) component fastening
  • Chassis and subframe structural joints
  • Onboard charger (OBC) and power electronics enclosures

🚗 Conventional Automotive & Commercial Vehicles

  • Engine block and cylinder head peripheral fastening
  • Transmission housing and gearbox covers
  • Suspension components, control arms, and knuckles
  • Brake caliper and disc shield mounting
  • Exhaust system heat shield fastening
  • Body-in-white (BIW) structural joints
  • Seat rail and safety restraint system anchoring

Why Choose FULLERKREG DIN 6921 Bolts?

  • ✅ Automotive-Grade Manufacturing: Produced in Wuhu, Anhui — China's premier automotive manufacturing hub, co-located with Chery Automobile's global headquarters. Our facility benefits from decades of automotive supply chain expertise.
  • ✅ Strict DIN Compliance: Every batch is manufactured and inspected to DIN 6921, DIN EN ISO 898-1, and DIN 267-11 standards.
  • ✅ Full Traceability: Material certificates (MTC), mechanical test reports, and coating inspection records available per shipment.
  • ✅ High-Volume Capability: Suitable for OEM and Tier-1 supplier procurement with consistent lot-to-lot quality.
  • ✅ Flexible Specifications: Both serrated and non-serrated flange types stocked; custom lengths, thread pitches, and packaging available.
  • ✅ RoHS & REACH Compliant: Surface treatment meets EU environmental directives for automotive exports.
  • ✅ Competitive Lead Times: Direct factory supply with efficient global logistics from Wuhu port access.

Applicable Standards & References

  • DIN 6921 — Hexagon bolts with flange (metric coarse thread)
  • DIN EN ISO 898-1 — Mechanical properties of fasteners: bolts, screws and studs (property class 10.9)
  • DIN 267-11 — Fasteners: technical delivery conditions — electroplated coatings
  • ISO 9227 — Corrosion tests in artificial atmospheres — salt spray tests
  • DIN EN ISO 4042 — Fasteners: electroplated coatings (hydrogen embrittlement relief)

Ordering & Customization

FULLERKREG supplies DIN 6921 Grade 10.9 Zinc Yellow bolts in standard and custom configurations. Please specify the following when placing an inquiry:

  • Thread diameter and pitch (e.g., M10 × 1.5)
  • Nominal length (e.g., 30 mm, 50 mm)
  • Flange type: Non-Serrated or Serrated
  • Required quantity and packaging (bulk / box / reel)
  • Certification requirements (PPAP, IATF 16949, etc.)

Contact our technical sales team for datasheets, samples, and volume pricing.

FULLERKREG — Precision Fasteners for the Automotive Future. Manufactured in Wuhu, China.

Sorry, this collection is empty.
Continue shopping