Historical
SAE J 473-1962 (SAE J473-1962)
Solders
The choice of the type and grade of solder for any specific purpose depend on the materials to be joined and the method of applying. Those with higher amounts of tin usually wet and bond more readily and have a narrower semi-molten range than lower amounts of tin. For strictly economic reasons, it is recommended that the grade of solder metal be selected that contains least amount of tin required to give suitable flowing and adhesive qualities for application.
Society of Automotive Engineers [sae]