We do not know exactly what Material and temper OEM cat rails are but we DO KNOW, that on any of our rails the temperatures required to cure the powder will affect the tempering of the material.
If a powdercoater is aware the material is sensitive and is conscious about running the lowest possible heat as well as running for the least amount of time possible there should be minimal affect to the material. Run it hot and let it bake for the longer side and your going to have yourself some weak rails.
This is why we ONLY anodize our rails as it has no affect on the material strength.
Get them painted if you do not want to worry about reducing strength.
