AutoCAD: Set Default Line Weight

I was editing a drawing that contains 50+ layers.

I notice that these layers default line weight were too thick and is too tedious to change each line weight one by one.

So the command to change to default line weight came useful.
“LWDEFAULT” (without the quote)

Other related command are:
LWEIGHT – Sets the current lineweight, lineweight display options, and lineweight units

And the most common command I use to draw line is “L”, Enter.