What is the shock shaft of a Losi 8ight RTR made out of?

I have a question about the RTR shock shafts fro the losi 8ight Buggy/truggy.
The shafts I have are silver/grey, what are they made out of? Al? Steel?
Also, the TiNi upgrade shafts (come in the kit as well I think?) I assume they are just TiNi coated, what are they made out of?
I noticed that I bent one of my rear shock shafts this weekend (among other broken parts) and I am hoping that the upgrade/kit shafts are made of a more durable material then the RTR shafts, so that if I do upgrade I will not run into this issue again.
Any help would be appreciated.

Thanks