What is the first step after seating the Hi-Lok pin flush in the countersink?

After seating the Hi-Lok pin flush in the countersink, the next step is to place the collar over the pin. This is a critical sequence in the assembly process, as the collar is designed to secure the Hi-Lok pin in place and ensure that it remains properly aligned during the subsequent installation steps.

Installing the collar after seating the pin serves to create a mechanical interlock, which is essential for the integrity of the fastened joint. Once the collar is properly positioned, it can then be locked in place using a specific tool, which completes the installation process and guarantees the strength required for the aerospace applications.

In this sequence, other steps like inserting a rivet or securing the assembly cannot occur until the collar is correctly in place. If adjustments were needed, they would typically happen before securing the collar, not after. Thus, placing the collar is the logical and necessary follow-up action after the pin is seated.