Material related issues
Won’t stainless steel get rust?
Stainless steel will rust under some certain conditions. Stainless steel resists to atmospheric oxidation – the anti-rust. Also stainless steel is anti-corrosion in the composition of acid, base and salty - the corrosion resistance.
But the limitation of its corrosion resistance will be changed by the steel’s chemical composition, reciprocal effect, the use of conditions and the environment types.
For example, SUS304 stainless steel tube in a dry and clean atmosphere can maintain an absolutely excellent resistance to anti-corrosion.
But if it is moved to the waterfront, because the sea-mist contains a lot of salt, it will rust soon. However SUS316 Stainless steel pipe still perform well under the same condition.
Therefore, not any kind of stainless steel in any environment can be corrosion resistance and can be anti-rust.
The surface treatment: Electropolishing or passivation, which finishing can get a better corrosion r
In general, electropolishing is used to flat surface of object. Passiviation is used to remove the micro material of surface.
Passiviation let parts surface form the inert passive state on surface of object, e.g. phosphate processing, so that the passivation can get the better corrosion resistance.
What difference is between copper and low-lead copper? Are they compliance with EU RoHS?
The difference between general copper and low-lead copper is the lead content. General copper is in exclusion provision of EU RoHS.
Copper alloy contains up to 4% lead = 40,000ppm which EU acceptable range. Low-lead copper, compared to the exemptions general copper, is fully RoHS compliant - lead content of 100 ppm of copper, which generally referred to as lead-free copper.
In addition, the copper cannot be completely lead-free because lead-free copper is not able to be manufactured and processed.
