IEC 60068-2-20:2021 is available as IEC 60068-2-20:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 60068-2-20:2021 outlines Tests Ta and Tb, applicable to devices with leads and leads themselves. Soldering tests for surface mounting devices (SMD) are described in IEC 60068‑2‑58. This document provides procedures for determining the solderability and resistance to soldering heat of devices in applications using solder alloys, which are eutectic or near eutectic tin lead (Pb), or lead-free alloys. The procedures in this document include the solder bath method and soldering iron method. The objective of this document is to ensure that component lead or termination solderability meets the applicable solder joint requirements of IEC 61191-3 and IEC 61191-4. In addition, test methods are provided to ensure that the component body can be resistant to the heat load to which it is exposed during soldering. This edition includes the following significant technical changes with respect to the previous edition:
- update of and clarification of pre-conditioning (former "aging") and its relation to natural aging.