If a material meets spec for a product designed to last 10 years, then you won't have to replace it in 10 years, assuming it's used properly. That's what "spec" means.
Having to replace something more frequently than stated usually either means improper use, or a knockoff using inferior materials.
One of the maintenance engineers at work sits across the corner from me. More than once we've had this talk: "yeah the machine was designed [read: specced] to use X material on this wear part, but if I can get this machine shop to make me the same part with Y material [read: exceeds spec] we won't have to replace the part nearly as often."
See also: iAbed RMS, aluminum water pumps