Sil-Fos 5 is a high-quality brazing alloy composed primarily of copper, with 5% silver and phosphorus. It is a self-fluxing brazing rod designed mainly for joining copper to copper and copper to brass. The phosphorus content acts as a built-in flux, eliminating the need for additional flux when brazing copper. This makes it ideal for HVAC, refrigeration, plumbing, and other copper-based brazing applications.