Super Corrosion-Resistant Stainless Steel Bolts

Do you know what kind of stainless steel bolts are used in the petroleum and chemical industries? Do not assume that the stainless steel bolts used in these industries are the same as the common 304 and 316 stainless steel bolts we usually encounter. The difference is actually enormous.

The stainless steel bolts used in petroleum and chemical applications are super corrosion-resistant grade. Their material grade is not 304, nor is it 316, but 904L. Just from the grade number, you can tell how high-performance this material is.

We usually refer to these bolts as 904L Super Austenitic Stainless Steel Bolts. They have a very high nickel content among all stainless steel bolts, while their carbon content is extremely low. In the early days, this material relied entirely on imports. Its corrosion resistance is extremely strong, and naturally, the cost remains high - you truly get what you pay for.

Because its application industries are relatively specialized, many professionals in the stainless steel bolt industry have rarely dealt with it, and some have never even heard of this super corrosion-resistant stainless steel bolt.

904L super stainless steel bolts can withstand sulfuric acid and other corrosive solutions of any concentration at approximately 70°C without being affected. The tank mounting sections of oil transport vehicles you see on the road are all locked with these super corrosion-resistant stainless steel bolts.

904L super stainless steel bolts have a lower carbon content than conventional stainless steel bolts and can undergo standard heat treatment without performance degradation. Due to the low carbon content, copper is added to the alloy, giving it excellent plasticity. It can easily form various non-standard parts and can also be passivated to achieve a higher surface finish.

It can be processed by various welding methods, formed by cold heading, or machined on a lathe. It is safe to say that super corrosion-resistant stainless steel bolts are the preferred fasteners for the petrochemical industry.

From the chemical composition data, we can see that 904L has a nickel content of about 25%, a carbon content of only 0.02%, and a higher copper content compared with ordinary stainless steel bolts.