Phase Diagram
To best understand solidification characteristics, the figure below shows a diagram of the tin-lead alloys illustrating the solid, pasty, or liquid state of any given tin-lead alloy at a given temperature (Note that complete solidification and melting are at the same temperature (362°F) for all tin-lead alloys).  While liquefaction of different percentages of tin-lead varies in temperature, the eutectic (quick melting) alloy with a mixture of 63% tin and 37% lead does not pass through a pasty stage.