What is the soldering material typically used for automobile radiator cores?

The soldering material commonly used for automobile radiator cores is typically a mixture of 45% tin and 55% lead. This combination provides an excellent balance of melting point, strength, and workability, which is essential for effectively joining the radiator components while ensuring reliable performance under the varying thermal conditions that automotive cooling systems experience.

The chosen ratio of tin to lead is significant. Tin enhances the solder's fluidity and improves corrosion resistance, which is crucial in the harsh environment of an automobile cooling system. Lead, on the other hand, lowers the melting point and helps with the ease of application. The specific 45/55% ratio is beneficial as it maintains a good degree of ductility and mechanical strength needed for the stresses encountered in radiators.

Other solder ratios, like those with higher or lower lead content, do not provide the same level of mechanical properties or may melt at inappropriate temperatures for automotive applications, thus making them less suitable for radiator soldering.