Durable Pants

I've been using these pants as an automotive technician for years because I like how roomy they are. The material is durable and the double knee is nice because I kneel on concrete floors a lot. The 2 main reasons I ever retire a pair are: 1. They've become too stained with nasty used oil and look dirty even after washing (if I'm lucky this doesn't happen for a couple years) or 2. (and this is my only real complaint with their quality) the stitching on the butt starts to separate and it looks like Winnie-the-Pooh's butt. No, I don't have an oversized butt. They really are tough pants that stay good looking for a long time!