Stainless steel nuts, bolts and screws: A4 - AISI 316

A4 AISI 316 stainless steel fasteners represent the gold standard for those who navigate, offering superior protection against corrosion compared to A2 steel. AISI 316, thanks to its chemical composition enriched with molybdenum, effectively resists the corrosive action of chlorides present in seawater, preventing sudden failures and costly repairs. Nautica Basile offers an assortment of nuts, stainless steel bolts, washers, set screws, pins, dowels, and other fasteners, all certified for nautical use and compliant with the highest quality standards.

Our assortment of A4 stainless steel screws is available both in practical standard packs and in bulk, allowing you to purchase exactly the quantity needed for your maintenance or repair work. Before placing your order, carefully verify the compatibility of the dimensions (pitch, length, diameter) with the original fasteners. Even a small discrepancy can compromise the tightness and safety of the fastening.

Why choose A4 fasteners over A2? The secret lies in the presence of molybdenum. AISI 316 (A4) contains molybdenum, which forms a protective barrier against chloride-induced corrosion. If your boat is moored in areas with high salinity or if you navigate frequently, the use of A4 fasteners is essential to ensure the durability and reliability of your fixings.

Sailing safely also means choosing the right materials. Nautica Basile's A4 fasteners offer you the peace of mind of a product designed to withstand the most extreme marine conditions.

The Basile Workshop Tip

• Fast Shipping: Orders received by 12:00 PM are shipped the same day.


• Satisfaction Guaranteed or Your Money Back: You have 14 days to return the product if you are not completely satisfied.


• Technical Advice: Do you have doubts about the compatibility or use of our products? Our team of experts is here to help. We have been at your service since 1982.

For extra protection against oxidation and to facilitate future disassembly, we recommend completing your order with our silicone grease specifically for nautical applications. Don't forget to consult our tools section, where you will find the ideal wrench or screwdriver for your fasteners.

What is the difference between A2 and A4 stainless steel? Which one should I use on my boat?

A4 stainless steel (AISI 316) contains molybdenum, which makes it significantly more resistant to chloride (saltwater) corrosion than A2 (AISI 304). In a marine environment, where exposure to salt is constant, A4 is the recommended choice to ensure durability and safety.

Can I use A2 fasteners instead of A4 if I can't find the part I need?

In emergency situations, you can temporarily use A2 fasteners, but it is essential to replace them with A4 as soon as possible. A2 will corrode more quickly, especially in areas exposed to salt water.

How can I protect stainless steel screws and bolts from corrosion?

Regularly apply silicone grease to the fasteners to create a protective barrier against salt water. Avoid contact with other metals (e.g. aluminum) that can trigger corrosive processes. Periodically inspect the fasteners and replace any parts that show signs of rust.

What does AISI 316 mean?

AISI 316 is the designation of a type of austenitic stainless steel, alloyed with chromium, nickel, and molybdenum. The acronym AISI (American Iron and Steel Institute) identifies the standard of chemical composition of the steel. The presence of molybdenum gives AISI 316 greater resistance to corrosion, especially in chlorinated environments such as the marine one.

What are the advantages of A4 stainless steel fasteners compared to other materials?

A4 stainless steel fasteners offer numerous advantages over other materials, including: high corrosion resistance, durability, mechanical strength, aesthetic appearance, ease of cleaning and maintenance. Furthermore, A4 stainless steel is a recyclable and environmentally friendly material.

Where can I use A4 stainless steel fasteners on my boat?

A4 stainless steel fasteners can be used in all areas of the boat exposed to salt water or humidity, such as: fastening deck fittings, building hydraulic systems, mounting engines and transmissions, fastening hardware and metalwork. In general, it is advisable to use A4 fasteners in all applications critical to the safety and reliability of the boat.

How can I choose the A4 stainless steel fasteners best suited to my needs?

To choose the A4 stainless steel fasteners best suited to your needs, it is important to consider several factors, including: the type of application, the load to which the fasteners will be subjected, the dimensions and type of thread required, the environmental conditions in which the fasteners will be used. If in doubt, do not hesitate to contact our technical support service for personalized advice.

What is the difference between A2 and A4 stainless steel? Which one should I use on my boat?

A4 stainless steel (AISI 316) contains molybdenum, which makes it significantly more resistant to chloride (saltwater) corrosion than A2 (AISI 304). In a marine environment, where exposure to salt is constant, A4 is the recommended choice to ensure durability and safety.

Can I use A2 fasteners instead of A4 if I can't find the part I need?

In emergency situations, you can temporarily use A2 fasteners, but it is essential to replace them with A4 as soon as possible. A2 will corrode more quickly, especially in areas exposed to salt water.

How can I protect stainless steel screws and bolts from corrosion?

Regularly apply silicone grease to the fasteners to create a protective barrier against salt water. Avoid contact with other metals (e.g. aluminum) that can trigger corrosive processes. Periodically inspect the fasteners and replace any parts that show signs of rust.

What does AISI 316 mean?

AISI 316 is the designation of a type of austenitic stainless steel, alloyed with chromium, nickel, and molybdenum. The acronym AISI (American Iron and Steel Institute) identifies the standard of chemical composition of the steel. The presence of molybdenum gives AISI 316 greater resistance to corrosion, especially in chlorinated environments such as the marine one.

What are the advantages of A4 stainless steel fasteners compared to other materials?

A4 stainless steel fasteners offer numerous advantages over other materials, including: high corrosion resistance, durability, mechanical strength, aesthetic appearance, ease of cleaning and maintenance. Furthermore, A4 stainless steel is a recyclable and environmentally friendly material.

Where can I use A4 stainless steel fasteners on my boat?

A4 stainless steel fasteners can be used in all areas of the boat exposed to salt water or humidity, such as: fastening deck fittings, building hydraulic systems, mounting engines and transmissions, fastening hardware and metalwork. In general, it is advisable to use A4 fasteners in all applications critical to the safety and reliability of the boat.

How can I choose the A4 stainless steel fasteners best suited to my needs?

To choose the A4 stainless steel fasteners best suited to your needs, it is important to consider several factors, including: the type of application, the load to which the fasteners will be subjected, the dimensions and type of thread required, the environmental conditions in which the fasteners will be used. If in doubt, do not hesitate to contact our technical support service for personalized advice.