Thats what I am slowly figuring out: When I look at the RATING of an item, it list its stats as 1 way - yet when you look at an item from its item level, it list it another. The TIER of the item is more based on the master component level than the individual parts, it seems.
I guess once I have dug into it deeper, I think what I should more accuratelly ask would be:
What are the RATING Tier Breakpoints for individual items? At what RATING is an item considered Tier 1/Tier 2/Tier 3?
When you select your crafting que (Armstech in my case) - you can filter them by RATING - where are the break points?
I don't know the rating #s, offhand tier 0 is under 120, tier 1 is the 120-126 Tionese stuff. Check the fleet vendors for the ratings on tionese, campaign, blackhole rattataki etc.. and it should give you some approximates for end-game tiers.