Have you encountered such a problem? The new nut has only been used for 2 months and rusty. Is it safe?
Although the two products are bright, the result of the neutral salt spray test are quite different:
First of all, the plating layer of the lug nut is: nickel + nickel + chromium
The anti-rust performance mainly depends on the nickel layer. The thicker the nickel layer, the stronger the anti-rust performance.
But nickel is very expensive, accounting for more than 80% of electroplating cost. In order to reduce the cost, some factories will make the nickel layer very thin, then increase the brightness by adding more brightener. The more brightener is used, the product will appear brighter. But the brightener will not play an effect on the anti-rust performance, so although B looks very bright, the nickel layer is very thin and the anti-rust performance is very poor.
When the quality of electroplating can’t be distinguished by your eyes, it is recommended that you can ask the supplier to issue a "salt spray testing commitment".The result of salt spray test can predict the rust - proof time of the product after loading on the car.
NSS testing TimeRust - proof time after loadingNote
Pass NSS 24h test2-3 monthsAs it snows in winter, the rusting will be accelerated due to salt spray on the road, so the rust-proof time will be greatly shortened. Therefore, it is recommended to increase the requirements of the salt spray test in winter.
Pass NSS 48h test5-6 months
Pass NSS 72h test10-12 months
Pass NSS 96h test1-1.5 years
Pass Cass 24h test2-3 years
Pass Cass 48h test5-6 years
We have our own electroplating line, can make different quality electroplating according to customer requirements. Our HONISHEN lug nuts can pass the NSS 72h test at least and the Cass 48h test at most.
The two products come from different manufacturers, and the bulge diameter is slightly different:
The bulge diameter of A is 23mm
The bulge diameter of B is 21.9mm
What is the effect of these size differences that are almost indistinguishable by the eyes?
When the bulge diameter of A is 23mm, the height of cone seat is 7mm
But when the bulge diameter of B is 21.9mm, the height of cone seat is only 6mm
The higher the cone seat, the greater the contact area with the hub, and more stable after installation.Therefore, A is superior to B.
Reducing the bulge diameter can save raw materials and the electroplating costs.It is also a cut corners for many factories. So please pay attention to the bulge diameter and the height of the cone seat when you purchase.
Many people think that when the product screws to the hub, if it can be very smooth screw up, the quality will be better.Actually, this is wrong.
If it's easy to screw on, when you're driving at high speed and bumping along, won’t the nut come loose more easily? The nut is loose and the hub is about to come off. Is it safe?
So it's not like the smoother the nut is the better. Instead, it is necessary to detect whether the thread accuracy of the nut is qualified by go-no go fixed gauges .
One end detects whether it can be screwed in completely;
The other end is tested to see if it can be jammed, and it must be jammed when it goes in at most 3 pitch. If it can also be screwed into the thread, it means that the thread is too large and loose, which is extremely unsafe.
Therefore, when you purchase, if some nuts are tightened by hand, there is no need to worry. As long as they can be screwed in, it is safer to tighten some nuts.
The verticality of the thread is very important. If the thread center is not correct, it will be tilted when installed on the hub, and the hub cannot be locked firmly, which will cause great safety hazards.
It can be judged whether it’s vertical by the professional testing equipment "Concentricity measuring instrument".
If there is no testing equipment, how to judge?
Screw the nut on the bolt slowly, and observe the state of the nut rotating to see if it is screwed in horizontally. If the nut is shaking up and down, and tilt rotating, it is a problem with verticality.
Although the lug nut is small, it involves the safety of each owner. We strictly implement the following quality control procedures to ensure that each product can be presented with high quality.
Trust the profession, choose HONISHEN.