A customer who manufactures hydrofoil panels once asked us, "Do your titanium screws rust?" We replied, "Titanium itself doesn't rust," but the customer remained skeptical: "Then why did the ones my friend bought develop white spots on the surface after just two months?"
This brings us to an often-overlooked fact about titanium alloys: while titanium doesn't rust, it can develop "fatigue spots." Chloride ions in seawater accumulate on the titanium surface over time, leading to crevice corrosion at the root of the threads-where stress concentrates. What appears to be white spots on the surface is actually microscopic pitting corrosion.
This is why some titanium screws appear to have white spots on their surface-it's not "rust," but rather hydrous oxide deposits formed when microscopic pitting corrosion pits merge into clusters. However, for users, "white spots" and "rust" are one and the same: they look unsightly and cause concern during use.
Our solution for hydrofoil clients is this: all screws must undergo nitric acid passivation before leaving the factory. The process is not complicated but requires extreme precision-the concentration, temperature, and duration of the acid pickling must all fall within strict parameters; even the slightest deviation is unacceptable. The essence of passivation is chemically accelerated oxidation-by immersing the titanium screws in a nitric acid solution of a specific concentration, the thickness of the artificial oxide film on the titanium surface is increased to 5 to 10 times that of a naturally formed film within a short period, and all microscopic pores in the oxide film are completely sealed. The main component of this film is titanium dioxide, which is "integrally grown" with the titanium substrate-it is not merely attached to it-so it will not peel off like a coating.
We also perform an additional step: before each batch of hydrofoil plate screws is shipped, we randomly select three screws and immerse them in artificial seawater for a 72-hour accelerated corrosion test. If even slight discoloration occurs, the technical department immediately returns the entire batch for re-passivation.
Finally, we sent samples to this client, who placed an order after testing them. We have now maintained a stable partnership with them for many years.
Sometimes, trust isn't built on a pile of certificates; it's proven through repeated efforts, year-after-year persistence, and one high-quality product after another.
Our company offers a one-stop service system covering everything from R&D and design to manufacturing and custom packaging. wthether youre a wholesaler wih your own brand or a manufacturer that uses titanium fasteners, our services save you the trouble of searching for suitable packaging or taking measurements.
Our address
Baoji City, Shaanxi Province, China
Phone Number
+86 133 9927 4269
sales@dtctitanium.com
