In addition to common cold galvanizing (electrogalvanizing) and hot-dip galvanizing, there is another surface coating process with extremely high corrosion resistance for bolts-Dacromet treatment. Originating from abroad, Dacromet is a relatively new surface coating technology for bolts, whose salt spray test duration far exceeds that of electrogalvanizing: standard-treated Dacromet bolts can withstand salt spray tests for hundreds of hours, and those with special enhanced treatment can even exceed 1,000 hours-a performance that electrogalvanizing can hardly match.

Common Grade 8 and Grade 4 nuts basically require electrogalvanizing treatment for three main reasons:

As core components in connection and fixing assemblies, the surface treatment of bolts not only affects their appearance but also plays a crucial role in their service life and overall performance. Adopting an appropriate surface treatment method can effectively improve bolts' corrosion resistance, wear resistance, and fatigue strength, thereby extending their service life and ensuring stable and reliable operation of equipment. Next, we will explore several common surface treatment methods for bolts, analyze their differences, and identify which method offers the best rust prevention effect.

Many of us think that bolts won't rust after galvanization, but this is not the case. Zinc plated bolts do not become completely rust-proof; instead, galvanization significantly extends the time it takes for them to rust. Therefore, when using bolts, it is crucial whether the selection of their surface treatment matches the environmental requirements-only by choosing a surface treatment method suitable for the service environment can the rust resistance of zinc plated bolts reach its optimal state.

​Stainless steel hex socket cap screws can remain rust-free for many years in the atmosphere, with core materials being SUS304 and SUS316 stainless steel. For screws that comply with national standard requirements, key dimensional tolerances can be measured and verified using conventional measuring tools such as calipers. Stainless steel hex socket cap screws are a general term for a specific category; since their performance is mainly determined by the material's own performance indicators, there is no need to subdivide them into too many subcategories when introducing such products.