The Fermat axis is the central line connecting the first and second Fermat points. It has line function
 |
corresponding to Kimberling center 
.
It passes through Kimberling centers 
for 
(symmedian point), 13
(first Fermat point), 14 (second
Fermat point), 113, 115 (center of the Kiepert
hyperbola), 265, 381, 399, 542, 1625, 1879, 1989, 2341, 2437, 2465, 2466, 3013,
3014, 3015, 3016, 3017, 3018, and 3019.
