How do leaded (Sn63/Pb37) and lead-free (SAC) solders differ?

Select one answer.

• Leaded melts lower (around 183 degrees Celsius), wets and flows easily, and is forgiving but toxic and RoHS-restricted; lead-free melts higher (around 217 to 220 degrees Celsius), wets less, needs more heat, and is RoHS-required for new commercial products.
• Leaded melts higher and is required for new products; lead-free melts lower and is banned everywhere.
• They are identical except for color.
• Lead-free contains more lead than leaded solder.