Tuzla is Turkey's shipbuilding centre, and everyone working here knows one truth: marine air devours materials. Salty humidity can destroy in months a fastener that would last years inland.
A2 (304) or A4 (316)?
- A2 (AISI 304): General purpose stainless — humid and indoor use. Weak against chlorides.
- A4 (AISI 316): Contains molybdenum, resistant to chlorides. For seawater and salt air, A4 is the correct choice.
Using A2 in a shipyard looks like a saving until pitting corrosion eats the joint from within.
When Is Hot-Dip Galvanising Enough?
Hot-dip zinc protects steel sacrificially and is economical for outdoor structures. But under constant seawater contact the zinc layer depletes. A sensible balance: A4 stainless at critical, hard-to-access points; hot-dip galvanised for large structures.
Galvanic Corrosion
- Stainless bolt + galvanised nut → the nut dissolves.
- Stainless fastener + aluminium body → the aluminium is eaten.
Solution: Keep material groups together, or isolate with insulating washers/bushings.
We have supported critical supply for the defense industry and shipyards since 2007. Contact us to determine the right grade together.
From Tuzla Civata: Since 2007 we have supplied the defense industry, shipyards, construction and manufacturing under engineer-led management. If you are unsure about product selection, get in touch — we will determine the right material together.