Old vs. new tappet/lifter delta

[a Wallace <wallaces@superaje.com>]

I just received a set of new lifters from British Parts Northwest. After 
speaking with (?) there, I elected to go with the heavy duty ones, since 
they have a hole in the side which makes since to me.
So they get here and look very different from the ones that came out, which 
look chrome plated. These are phosphated.
What is phosphating? The surface doesn't seem as smooth - is so that oil 
can "hang on" better? I normally equate rougher with more wear, which I do 
not want.
Jim
 >60K 3a