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DIN 985 Class 4 Zinc Finish Steel Nylon Insert Lock Nut

DIN 985 Hexagon Nylon Insert Lock Nuts – Class 4 Zinc Finish Steel (ML08AL)

FULLERKREG DIN 985 Class 4 nylon insert lock nuts are manufactured from ML08AL low carbon steel with a Zinc Cr3 (trivalent chromium) electroplated finish, delivering reliable corrosion protection and a clean, uniform appearance. The integrated nylon collar creates a friction-based prevailing torque that resists loosening under vibration and dynamic loads — without damaging the mating thread. A cost-effective solution for general mechanical assemblies, automotive components, and industrial equipment where carbon steel performance is required.

Product Specifications

Attribute Details
Standard DIN 985 / ISO 7042
Type Hexagon Nylon Insert Lock Nut (Prevailing Torque)
Material ML08AL Low Carbon Steel (Q195 equivalent)
Strength Class Class 4
Surface Finish Zinc Cr3 (Trivalent Chromium Electroplating)
Zinc Layer Thickness ≥ 5 μm (standard); ≥ 8 μm available on request
Thread Metric Coarse Thread (ISO 68-1)
Size Range M3 – M20
Insert Material Nylon (Polyamide PA66)
Temperature Range -40°C to +120°C
RoHS Compliant Yes (Cr3 / Trivalent — no hexavalent chromium)
Brand FULLERKREG

Dimensional Data (DIN 985 – Class 4, Metric)

All dimensions in millimeters (mm). Unit weight (单重) is approximate reference value.

Nominal Size Pitch (mm) F – Width Across Flats Max (mm) F – Width Across Flats Min (mm) G – Width Across Corners Min (mm) H – Thickness Max (mm) H – Thickness Min (mm) I – Wrenching Height Min (mm) 单重 (g/pc)
M3 0.5 5.50 5.32 6.01 4.0 3.7 2.4 ~0.6
M4 0.7 7.00 6.78 7.66 5.0 4.7 2.9 ~1.2
M5 0.8 8.00 7.78 8.79 5.0 4.7 3.2 ~2.0
M6 1.0 10.00 9.78 11.05 6.0 5.7 4.0 ~3.5
M7 1.0 11.00 10.73 12.12 7.5 7.14 4.7 ~5.5
M8 1.25 13.00 12.73 14.38 8.0 7.64 5.6 ~7.5
M10 1.5 17.00 16.73 18.90 10.0 9.64 6.5 ~14
M12 1.75 19.00 18.67 21.10 12.0 11.57 8.0 ~23
M14 2.0 22.00 21.67 24.49 14.0 13.3 9.5 ~37
M16 2.0 24.00 23.67 26.75 16.0 15.3 10.5 ~55
M18 2.5 27.00 26.16 29.56 18.0 17.66 13.0 ~78
M20 2.5 30.00 29.16 32.95 20.0 19.7 14.0 ~110

* Dimensions per DIN 985 / ISO 7042. Unit weight values are approximate and for reference only. Carbon steel density ≈ 7.85 g/cm³. Actual weight may vary slightly by batch.

Zinc Cr3 Surface Finish – Technical Notes

Property Zinc Cr3 (This Product) Plain / Black Oxide
Chromium Type Trivalent Cr3 (RoHS compliant) N/A
Salt Spray Resistance ≥ 72 hrs (white rust); ≥ 120 hrs (red rust) Very low (< 24 hrs)
Appearance Bright silver / slight blue iridescence Matte black / grey
RoHS / ELV Compliant Yes Yes
Typical Application General industrial, automotive, machinery Indoor / dry environments only

Selection Guide

Application Scenario Recommended Size Key Consideration
General machinery & equipment M6 – M16 Cost-effective vibration-proof fastening
Automotive body & chassis M8 – M16 Zinc Cr3 meets OEM corrosion requirements
Electronics & appliance enclosures M3 – M6 Small sizes, clean finish, RoHS compliant
Steel structures & brackets M10 – M20 High volume, economical Class 4 grade
HVAC & ductwork M6 – M12 Vibration resistance in air-handling systems

Standard & Compliance

These nylon insert lock nuts are manufactured in full compliance with DIN 985 and the equivalent international standard ISO 7042. Mechanical properties conform to ISO 898-2 Class 4. Surface treatment meets ISO 4042 (electroplated zinc coatings) with trivalent chromate passivation (Cr3), fully compliant with RoHS 2011/65/EU and ELV 2000/53/EC directives — no hexavalent chromium (Cr6).

  • Proof Load (N/mm²): 510 (Class 4)
  • Hardness: 188 HV max
  • Applicable bolt class: Class 4.8 or less
  • Salt spray test: ≥ 72 hrs white rust / ≥ 120 hrs red rust (per ISO 9227)

Product Gallery

DIN 985 Class 4 Zinc Finish Steel Nylon Insert Lock Nuts – actual product photos:

       

Why Choose FULLERKREG?

  • 🏭 Direct Manufacturer – Factory-direct pricing with no middlemen, ensuring competitive wholesale rates
  • ✅ Strict Quality Control – 100% dimensional inspection; salt spray test reports and material certificates available on request
  • 📦 Flexible MOQ & Packaging – Custom packaging quantities, OEM labeling, bulk bag or box options
  • 🚢 Global Shipping – FBA-ready shipments to Amazon warehouses; direct export to 50+ countries
  • 🔬 Engineering Support – Technical datasheets, CAD drawings, and application guidance available
  • ⚡ Fast Lead Times – In-stock items ship within 3–5 business days; custom orders within 15–25 days

Frequently Asked Questions

Q: What is the difference between Zinc Cr3 and Zinc Cr6 (yellow zinc)?
A: Cr3 uses trivalent chromium passivation and is fully RoHS / ELV compliant with no hazardous hexavalent chromium. Cr6 (yellow zinc) offers slightly higher corrosion resistance but is restricted under EU environmental regulations. FULLERKREG supplies Cr3 as standard for all zinc-plated products.

Q: Can DIN 985 Class 4 nylon lock nuts be reused?
A: They can be reused a limited number of times. For critical or safety-relevant joints, single-use is recommended as the nylon insert loses prevailing torque effectiveness after repeated cycling.

Q: What is the difference between DIN 985 and DIN 982?
A: DIN 985 is a thin (low-profile) nylon insert lock nut; DIN 982 is the full-height version. DIN 985 suits space-constrained assemblies; DIN 982 provides higher prevailing torque retention.

Q: What bolt class should be used with Class 4 lock nuts?
A: Class 4 nylon insert lock nuts are designed for use with Class 4.8 bolts or lower. For higher-strength bolts (8.8, 10.9), please select Class 8 or higher grade nuts.

Q: Do you provide material test certificates and salt spray reports?
A: Yes. Material test certificates (MTC), RoHS declarations, and salt spray test reports (ISO 9227) are available upon request for all orders.

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