The difference between lead-free copper-containing tin bars and
pure tin bars can generally be distinguished from the following aspects:
1. Judging from the glossiness of the appearance: lead-free tin bars are bright yellow; leaded tin bars are bright white.
2. In terms of packaging: lead-free tin bars are generally in green boxes, and there is a ROHS logo on the box.
The lead tin bar is a gray box, and the box is marked with electrolytic tin bar or anti-oxidation lead solder bar.
3. From the composition difference:
1. The composition of tin bars with lead is composed of tin and lead. The commonly used ingredients are Sn63Pb37. Melting point of 6337 tin bars: 183°
It is suitable for wave soldering and hand furnace. After selected electrolytic purification and special refining and melting special process, the impurity elements and fine oxidation substances in the solder are greatly removed, and a small amount of anti-oxidation elements are added to the 6337 solder bar.
2. The composition of lead-free tin bar is composed of tin, copper and silver, and the commonly used composition is Sn99.3Cu0.7. Lead-free tin bar (EU ROHS standard is less than 1000PPM lead content, Japanese standard is less than 500PPM). Melting point of lead-free tin bar: 227°.