What are the most commonly used solders for making joints on copper tube?

The two most commonly used solders for making joints on copper tube are indeed 50-50 tin-lead and 95-5 tin-antimony. The 50-50 tin-lead solder has been widely used because of its excellent flow properties and the ability to create strong, reliable joints. It has a relatively low melting point, which makes it suitable for joining copper tubes without damaging the copper itself.

Similarly, 95-5 tin-antimony solder is also effective for copper tube applications, providing good mechanical strength and resistance to corrosion. This solder has benefits that make it suitable for plumbing applications, especially under conditions where the joints might be exposed to varying environmental factors.

In terms of the other options, while 100% tin solder can be used, it is generally not as preferred for plumbing applications due to its limited wetting properties and higher melting point. Lead-free alternatives are becoming more commonly adopted due to health regulations, but they vary in composition and are not yet as traditional as the tin-lead or tin-antimony solders. The 50% silver and 50% copper solder is often associated with specific uses, like brazing, rather than standard soldering for copper tubing. Thus, the established standards in the industry favor