Hexakaidecagon (16 sided) in my control arm bushing...
 

Question for the masses;

In prepping my body for the inner poly-bronze bushing I noticed a hexakaidecagon pattern (seemed to be 16 sided) in that housing on the body. It seems as this was some sort of steel sleeve that rusted in that bearing area. Have you had any experience with this in the past? At first I thought it was just a strange rust pattern but, I worked my grinder around the area and I could count 16 rather symmetrical flat sides within.

Any insight is appreciated.