The Zinc Plated Nylon Insert Lock Nut (commonly referred to as a nyloc nut, self-locking hex nut, prevailing torque nut, or DIN 985 / ISO 7040 locknut) is an essential anti-loosening internally threaded fastener engineered with an unthreaded elastic polyamide (nylon 66) collar crimped into its upper crown. When threaded onto a bolt or rod, the male thread cuts into the nylon ring, forcing the elastic material to compress and grip the bolt flanks tightly. This prevailing torque friction prevents joint loosening caused by continuous dynamic vibration, shock loads, and thermal expansion in accordance with global ISO standards.
Technical Specifications of Zinc Plated Nylon Insert Lock Nut
We produce Class 4 low-carbon steel nylon insert lock nuts ideal for general machinery, HVAC equipment, and agricultural assemblies. The electro-deposited blue-white trivalent zinc layer (Cr3+) protects the steel body against indoor and outdoor atmospheric oxidation, while the high-grade nylon ring operates reliably across temperatures from -40°C to +120°C.
| Parameter | Class 4 Zinc Plated Nyloc Nut | Class 6 / 8 High Tensile Nyloc Nut |
|---|---|---|
| Core Material Grade | Low Carbon Steel (Q195 / Q235B) | Medium Carbon Steel (35# / 45#) |
| Proof Load Stress (Min) | 400 N/mm² (400 MPa) | 600 – 800 N/mm² (600–800 MPa) |
| Locking Element Material | High-Elasticity Polyamide (Nylon 66 Ring) | High-Elasticity Polyamide (Nylon 66 Ring) |
| Operating Temperature Range | -40°C to +120°C (-40°F to +248°F) | -40°C to +120°C (-40°F to +248°F) |
| Surface Zinc Protection | 5 µm – 12 µm Electro-Zinc Plated (Cr3+) | 5 µm – 15 µm Electro-Zinc Plated (Cr3+) |
Precision Manufacturing and Nylon Ring Crimping Process
At our specialized manufacturing facility in Handan, China, nylon insert lock nuts undergo multi-station cold forming, precision internal tapping, automated collar ring insertion, and electro-galvanizing:
- Multi-Station Cold Heading: High-speed cold formers press carbon steel wire rod into metric hexagonal body dimensions and form the internal upper retaining groove.
- Precision Internal Thread Tapping: Automatic tapping units thread metric 6H internal pitches to ensure low installation friction prior to engaging the nylon ring.
- Automated Ring Insertion & Crimp Ringing: Precision robotic assembly units place the pre-molded nylon ring into the groove and roll-crimp the top steel lip over to lock the collar permanently in place.
- Electro-Zinc Plating & Passivation: Chemical washing strips scale, followed by galvanic zinc deposition and Cr3+ blue-white passivation for clean corrosion protection.
Anti-Vibration Applications of Zinc Plated Nylon Insert Lock Nuts
Nylon insert lock nuts provide self-locking security without requiring additional lock washers, cotter pins, or chemical threadlockers, making them ideal for dynamic mechanical assemblies:
- Automotive & Chassis Assemblies: Securing suspension linkages, bumper brackets, steering components, and engine accessory mounts subjected to road vibration.
- Electric Motors, Generators & Compressors: Fastening motor mounting feet, fan housings, and pump bases subjected to continuous rotational movement.
- Agricultural Equipment & Lawn Mowers: Securing tractor implements, rotary mower blades, and conveyor frames operating under harsh outdoor vibration.
Quality Assurance and Export Packaging for Nylon Insert Lock Nuts
Handan YiHao Fastener enforces strict Quality Assurance (QA) standards for all overseas export shipments. Inspection procedures include prevailing torque and breakaway torque testing, nylon ring pull-out resistance verification, 6H thread plug gauge pass/fail checks, and coating thickness checks.
All export items are packed in heavy-duty 25kg inner cartons, neatly stacked on ISPM 15 compliant fumigated wooden pallets, and shrink-wrapped for safe maritime transit.
Request Factory Direct Pricing for Zinc Plated Nylon Insert Lock Nuts
Looking for a trusted manufacturer in Handan, China for Class 4 or Class 6 zinc-plated nylon insert lock nuts (DIN 985 / ISO 7040)? Contact Handan YiHao Fastener today for technical datasheets, torque performance reports, free samples, and direct bulk export quotes.
