What type of solder is best for electrical connections and bunch tinning of stranded conductors?

Resin core solder is the most suitable choice for electrical connections and bunch tinning of stranded conductors due to its composition and properties. This type of solder incorporates a rosin-based flux within the core, which helps to clean the metal surfaces as it melts, facilitating better adhesion and creating a secure, conductive bond.

When working with stranded conductors, bunched tinned wire strands must be effectively coated to ensure electrical continuity and prevent oxidation. The rosin flux in resin core solder aids in this process by removing any oxidation or impurities that could hinder solder adhesion. This action creates a strong mechanical connection as well as an excellent electrical connection.

Lead-free solder is often used in various applications due to regulations regarding lead content, but it may not provide the same ease of use and effectiveness when it comes to electrical applications as resin core solder. Tinning solder and flux solder do not inherently provide the same combination of cleaning and bonding properties as resin core solder, making them less ideal for connecting strands securely.