Review on 🔌 MG Chemicals Leaded Solder: Superior Diameter Solution for Industrial Power & Hand Tools by Marco Hubbard

63/37 The solder is called eutectic solder, which means it melts instantly at the right temperature. 60/40 solder has an area where it softens but isn't ready to make a strong connection, and as the temperature rises it's ready to make a good connection. The melting range is fine, but as a beginner solderer I found it helpful to know that when melting the eutectic solder I was at the right temperature to form a good joint.