- ZHUHAI JIALI HARDWARE CO.,LTD.
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Environmentally friendly black zinc external serrated washer, external multi tooth washer, lighting lock washer
- Product description：zinc external serrated washer
Environmentally friendly black zinc external serrated washer, external multi tooth washer, lighting lock washer ，From the perspective of anti-loosening mechanism, the "external-tooth structure" of the eco-friendly black zinc external-tooth washer represents a core breakthrough in enhancing fastening performance. The edge of this washer is evenly distributed with 8-12 sharp outward-facing teeth, with the tooth height controlled between 0.2-0.4mm and the tooth pitch precisely set to 1.5-2mm. This dimensional design not only ensures that the teeth can easily embed into the surface of the connected component (such as the aluminum alloy lamp holder of lighting fixtures or the steel bracket of outdoor equipment) but also avoids damaging the workpiece due to excessively deep teeth. When the bolt is tightened, the teeth act like "mechanical pawls," firmly engaging with the connected component and the bolt head to form a dual anti-loosening system of "physical locking + friction enhancement": on one hand, the engaging structure of the teeth directly prevents the bolt from rotating in the reverse direction caused by vibration, completely cutting off the "source of loosening"; on the other hand, the close contact between the teeth and the workpiece significantly increases the friction coefficient (measured to be 0.55-0.6, far exceeding the 0.3-0.4 of ordinary flat washers), further strengthening the fastening stability.
Third-party test data shows that in a simulated daily vibration environment of 5-500Hz, the M6 bolt paired with the eco-friendly black zinc external-tooth washer still maintains a preload retention rate of up to 92% after 20,000 vibration cycles; in contrast, the preload retention rate of bolts using ordinary flat washers is only 65%, and that of spring washers can only maintain 78%. This anti-loosening advantage is particularly crucial in the lighting field: take a crystal chandelier weighing 5-10kg as an example, ordinary flat washers are prone to gradual loosening of bolts due to the chandelier's own weight and vibration from the ventilation system over the long term, leading to the chandelier tilting; however, the engaging structure of the eco-friendly black zinc external-tooth washer can firmly lock the suspension rod and the lamp holder, and even after more than 5 years of use, it can still maintain stable fastening, fundamentally eliminating the risk of loosening.
The eco-friendly black zinc process provides "escort" for fastening performance from the perspective of weather resistance. Although ordinary galvanized washers have basic rust resistance, their coatings are prone to peeling and rusting in harsh environments such as humidity and salt spray. This not only weakens the fastening friction but may also cause the bolt to seize or loosen due to rust expansion. In contrast, the eco-friendly black zinc external-tooth washer adopts a three-layer process of "zinc-nickel alloy plating + chromium-free passivation + black organic sealing layer": first, an 8-12μm thick zinc-nickel alloy plating is formed through electroplating, whose corrosion resistance is more than 3 times that of ordinary galvanizing; then, chromium-free passivation treatment is carried out to avoid heavy metal pollution from traditional hexavalent chromium passivation while enhancing the coating adhesion; finally, a black organic sealing layer is applied to further isolate moisture, oxygen, and corrosive media.
In the neutral salt spray test (ASTM B117), this washer can achieve 72 hours of no red rust, far exceeding the 24-48 hours of ordinary galvanized washers. This performance has significant advantages in outdoor equipment scenarios: for example, in the connection between the pole and base of LED lawn lights in parks, which are long-term exposed to alternating environments of rainwater, dew, and high temperatures, ordinary washers tend to rust within 3-6 months, leading to base loosening; however, the eco-friendly black zinc external-tooth washer can still maintain the integrity of the coating even after more than 2 years of use, with no obvious attenuation of bolt fastening force, ensuring the pole remains upright and stable, and avoiding the risk of tipping caused by loosening.
In addition, the adaptable design of the eco-friendly black zinc external-tooth washer further amplifies the application value of its fastening performance. Its dimensional tolerance is strictly controlled within ±0.05mm, enabling it to accurately match bolts of M4-M12 specifications and meet the fastening needs of various scenarios such as lighting fixtures, electronic equipment, and small machinery. Meanwhile, the matte black eco-friendly black zinc coating not only complies with international environmental standards such as RoHS and REACH but also integrates with the appearance design of modern equipment. For example, in the angle adjustment components of shopping mall window spotlights, the metallic luster of traditional washers easily damages the overall aesthetic of the lamp and tends to loosen after adjustment; in contrast, the eco-friendly black zinc external-tooth washer can lock the adjusted angle through tooth engagement to avoid position deviation caused by slight collisions, while seamlessly matching with the black lamp body, balancing both fastening performance and aesthetic needs.
In automated production scenarios, the consistency and stability of this washer also provide guarantees for fastening performance. Its standardized tooth structure and coating process can adapt to the high-speed feeding and tightening processes of automated assembly equipment, avoiding uneven fastening caused by washer dimensional deviations or coating peeling. At the same time, its characteristic of being reusable 3-5 times eliminates the need for frequent washer replacement during equipment maintenance, which not only reduces costs but also maintains stable fastening performance. For instance, during the maintenance of recessed downlights, the washer reinstalled after disassembly can still maintain more than 85% of its anti-loosening capability, far surpassing the disposable ordinary external-tooth washers.
