Are Aqueon & Topfin 55gal sides Tempered?

[nacra99]

I have found lots of specs that tell me that the BOTTOM is tempered, but does anyone know if the SIDES are tempered? Particularly the back (or front) panels.

I would like to put a 1-1/2" hole for a bulkhead through a coupla 55 gal tanks to build a centralized system.

thanks!