Product Summary

Longze Nylon Insert Lock Nuts (DIN 985 to ISO 7040) are the industry standard for preventing fastener loosening under high vibration و 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، أو 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: ملكنا 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 و 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
  Carbon Steel	18 - 30 HRC	Class 8	Grade 8.8 Bolts
  Carbon Steel	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
  م12	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: عند الاستخدام 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 مشتمل Prevailing Torque Testing, thread gauging، و 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.