It’s a fact that the lead-free solder alloys had caused an increase in the usual soldering temperatures, but there still are lots of applications involving heat-sensitive devices, where the usual 400°C or higher temperatures can cause real problems.
Recognizing this issue, Hakko had introduced a new series of tips for the FX-100 soldering systems featuring the new Induction Heater technology, with the core temperature of 350°C. These new tips are called series 3 (just remember that for these systems, the series 1 tips are heated by a 450°C heating core, and series 2 are the 400°C tips). The available geometries are the same as for series 1 and 2. The part number is built in the similar way: T31-03xxx, where xxx stands for the usual geometry code.
You can clearly differentiate the series 3 tips, due to their white connectors, in contrast with the black connectors of series 1 and 2. Hakko plans to introduce a unique colour coding for the different temperature tip series.
The new low temperature tip series are targeting mainly the manufacturing and repair sites for automotive and medical devices, as the temperature limits in these areas are usually more restrictive than in other sectors. However, using lower temperatures can be beneficial in any applications, in the terms of tip life. As a rule of thumb, you should always use the lowest temperature that can do the job.