I'm a fan of Gfeller casemakers leather goods, including belts. They make leather goods primarily for field geologists, and if you've ever known a field geologist you know they need extremely durable goods.

It is pricey, but it's also a pretty small company.

I have my mom's old Bamix from a long time ago (I've owned it for 10ish years, my mom owned it for decades before that). And both of us have used it heavily. Still works a dream.

It's amazingly well made.