I did some reasearch. It looks like LM25 refers to a specific aluminum alloy. I think the KD refers to something about how it is finished.
The context is this sentence describing the wheels of one of my cars from the shop manual:
The wheels are four bold locating aluminum alloy LM25KD with 45 ribs equally spaced at 8º, with windows between.
I am just curious what the KD means and how I might look something like that up.