Product Summary

Longze Nylon Insert Lock Nuts (DIN 985 to ISO 7040) are the industry standard for preventing fastener loosening under high vibration et dynamic loads. Manufactured in Yongnian, China,

our lock nuts feature a high-resilience nylon collar that creates a frictional interference fit with the bolt thread. Whether for automotive suspension, agricultural machinery, ou solar racking systems, Longze lock nuts provide the permanent clamping force required for safety-critical assemblies.

• ✔ Superior Vibration Resistance: The integrated nylon ring deforms elastically over the bolt threads, providing a constant prevailing torque.

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• ✔ Reusable Performance: Notre premium-grade nylon inserts retain their elastic memory, allowing for multiple assembly cycles.

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• ✔ Full Material Traceability: Every batch is tested for torque-out strength et thread consistency, ensuring 100% reliability.

• Standards: DIN 985, ISO 7040, UNI 7473.

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• Size Range: M3 to M48 (Full metric stock available).

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• Material Grades: Carbon Steel (Class 8 to 10) | Stainless Steel 304/316 (A2/A4).

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• Surface Hardness: 100HV to 300HV (Depending on Property Class).

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• Surface Finish: Hot-Dip Galvanized (HDG), Zinc Plated, Black Oxide, Plain.

Mechanical Properties & Material Standards

• Matching the hardness and tension requirements for extreme industrial vibration.

• Material Type	Core Hardness	Surface Hardness	Tensile Support
  Acier au carbone	18 - 30 HRC	Class 8	Grade 8.8 Bolts
  Acier au carbone	32 - 39 HRC	Class 10	Grade 10.9 Bolts
  SS304 / SS316	140 - 200 HV	A2-70 / A4-80	Corrosion Resistant

Standard Dimensions (Metric)

• Common dimensions for standard metric nylon insert lock nuts.

• Thread Size (D)	Pitch (P)	Height (h)	Across Flats (s)	Weight (kg/100pcs)
  M8	1.25 mm	8.0 mm	13.0 mm	0.51 kg
  M10	1.50 mm	10.0 mm	17.0 mm	1.16 kg
  M12	1.75 mm	12.0 mm	19.0 mm	1.72 kg
  M16	2.00 mm	16.0 mm	24.0 mm	3.40 kg

Galvanizing & Corrosion Resistance

• Ensuring 20+ years of service life in corrosive environments.

• Surface Treatment	Process	Salt Spray Test	Best Application
  Hot-Dip Galv.	Molten Zinc	500 - 800 Hours	Outdoor / Marine
  Zinc Plated	Electrolytic	72 - 144 Hours	Indoor Structural
  Black Oxide	Chemical	< 72 Hours	Internal Machinery

Avoid Pitfalls:

• Grade Matching: Never use a lower-grade nut with a higher-grade bolt (e.g., Class 8 nut on a 10.9 bolt). This leads to thread stripping before the bolt reaches its design tension.

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• Lubrication Management: Nylon lock nuts work by friction. Excessive lubrication on the nylon insert can reduce the prevailing torque. Longze provides specialized Torque-to-Tension charts to prevent overstretching.

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• Reuse Guidelines: While reusable, the nylon insert wears down. If the nut can be turned past the nylon ring by hand, replace it immediately to ensure vibration resistance.

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Perfect Fit Assembly:

• Coating Compatibility: Lors de l'utilisation Hot-Dip Galvanized (HDG) nuts, ensure the matching bolt is also HDG and appropriately over-tapped to maintain thread fit without compromising the nylon seal.

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• Orientation: Always install the nut with the flat metal surface facing the work-piece and the nylon-insert collar facing outward.

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• Matching Components: Pair with Longze DIN 931/933 Bolts to ensure full thread engagement through the locking element.

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Quality Control & Logistics:

• ISO 9001 Certified: 5-step QC y compris Prevailing Torque Testing, thread gauging, et 100% visual inspection of the nylon ring.

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• Sea-Worthy Packaging: Fumigation-free pallets, wooden cases, cartons with inner plastic bags, 25kg cartons. Secured for maritime export from our Yongnian hub.

• Q: Can I use these with wedge-lock washers? A: Generally not necessary. Nylon nuts use friction, while wedge-washers use tension. For extreme safety-critical joints, wedge-washers are preferred.

• Q: How does the nylon handle temperature? A: Longze uses premium nylon that remains stable from -40°C to +120°C, maintaining its prevailing torque even in harsh environments.