Silicon Bronze Fasteners

What are silicon bronze fasteners?

Silicon bronze fasteners are manufactured from a copper–silicon alloy designed to resist corrosion across a wide range of substances. Compared to brass, silicon bronze offers improved durability while retaining good conductivity and an attractive natural finish. In applications where wear resistance or fatigue performance is critical, silicon bronze fasteners are often specified alongside phosphor bronze fasteners, with final material selection based on service environment and mechanical requirements.

What grades of silicon bronze fasteners are available?

Silicon bronze fasteners are typically supplied in the following grades:

• Silicon Bronze 651 (C65100): Also known as Low Silicon Bronze B, this alloy contains 0.8–2% silicon and offers moderate strength, high thermal conductivity and good corrosion resistance in both freshwater and saltwater environments. It has a typical melting point of around 1030°C, making it suitable for marine applications above and below the waterline.
• Silicon Bronze 655 (C65500): Often referred to as High Silicon Bronze A, this grade contains 2.8–3.8% silicon, providing increased strength and improved resistance to acids, alkalis and organic chemicals. This higher silicon content reduces conductivity and lowers the melting point to approximately 970°C, making it suitable for chemical processing applications.

Products are available in a range of sizes and grades, either from stock or manufactured to order, typically with short lead times. Many existing Fastenright products can be manufactured in silicon bronze on request. Non-standard sizes, grades and finishes are available as specials, and bespoke components can be produced to drawings and specifications, subject to minimum order quantities.