Fasteners are an essential component of the maritime industry, where they are used in a variety of applications, including shipyards, boats, yachts, fishing vessels, merchant vessels, boat accessories, offshore energy systems, pipelines, etc. In the marine industry, mechanical fasteners are often the preferred choice due to their strength and security.
The choice of fasteners for the maritime industry
One of the main considerations when choosing fasteners for the marine and nautical industry is corrosion resistance. Salt water, in fact, is highly corrosive due to the high concentration of dissociated ions.
When choosing fastening solutions for use in the maritime sector, it is essential to focus on corrosion-resistant materials.
Austenitic stainless steels are often recommended because they have a stronger passive film. The best known is AISI 316 Low Carbon (A4): Cr (16.5/18.5%) / Ni (10.5/13.5%) / Mo (2/2.25%) / C (< 0.03%) with a PREN (Pitting Resistance Equivalent Number) value, which indicates the material’s ability to resist pitting, between 25 and 28.
In critical situations, where even higher corrosion resistance is needed, certain surface finishing treatments such as passivation, electropolishing or special galvanic coatings can be considered.
In applications where high mechanical properties are required in addition to corrosion resistance, it would be advisable to use super austenitic or austenitic-ferritic duplex or super duplex steels.
More specifically, AISI 316L (A4) stainless steel is known for its excellent corrosion resistance, especially in marine environments, and has better mechanical properties at high temperatures than other types of stainless steel. It is commonly referred to as ‘marine grade steel’ because of its exceptional resistance to intercrystalline or intergranular salt corrosion. For more information on stainless steels and their characteristics, read this in-depth article.
In addition to corrosion resistance, the mechanical properties of fasteners are also crucial in the design and construction of marine equipment. Fasteners must be able to withstand the various pressures, impacts and potential leaks they may be subjected to in the marine environment.
In conclusion, fasteners play a vital role in the marine industry and it is important to carefully consider the material, design and installation of these components to ensure the success of any project.
Specialinsert® fastening solutions for the marine industry
Specialinsert® offers a wide range of high quality fastening systems, designed and manufactured in Italy, to meet the needs of the maritime sector. Our products include:
- KEEP-NUT®,, a versatile insert that allows threads to be created on slabs of marble, granite and other stone materials, as well as on composite materials, carbon, Corian®, HPL, glass and other solid surfaces, even thin ones. Quick and easy to install, KEEP-NUT® is made of stainless steel.
- FAST-CON®, a patented stainless steel snap-on metal fastening system that allows panelling and cladding to be easily connected. A concealed, corrosion- and flame-resistant and long-lasting solution. In the maritime sector, FAST-CON® can be used to fix panels and cladding in boats and ships. In addition, its small footprint makes it ideal for use in confined spaces on board boats.
- MASTER-PLATE®, a fixing system that uses adhesives to be attached to any type of material. It can also be used with screws, rolling or co-moulding. The base plate can be fitted with a threaded or unthreaded attachment and can take various shapes. It is produced in both galvanised steel and AISI 316L stainless steel.
- DEFORM-NUT®, a metal threaded tubular rivet with a deformable expansion chamber at the top to anchor to the material. It can be installed on parts where there is no possibility of access to the inside (e.g. tubes, sheet metal, section bars, box-structures, etc.) and is easy and quick to install, versatile, aesthetic and with high mechanical sealing characteristics. The product is also available in AISI 316 stainless steel and in titanium (DEFORM-TI® series).
Undecided which fastener is best suited to your needs? Fear not, Specialinsert® offers a dedicated service at every stage of a project’s development, providing advice and support in choosing the best fastener solutions.
Our technical team is available to answer questions and solve any problems both when using the products and when designing custom systems for the marine industry.
