I just checked my garmin, and just so you know, because I did not, my zone 5 starts at 185 and there is no zone 6, so my terms in this whole back and forth have been based on my zone 5 being basically close to the zone 6 on the chart.

usually around 188 I feel like I can't maintain this for longer than a few minutes.
anything below 180 is generally just riding really hard, but by no means "hammering"