The fabric comparison is a draw
Carhartt firm duck is 12oz cotton canvas. Duluth’s Fire Hose is a heavy cotton canvas in the same class, named after the material fire hoses were once made from. Both abrade slowly, both are brutally stiff for the first month, both patch well.
People argue about which is tougher and the honest answer is that ordinary use will not separate them. Anyone claiming a dramatic difference is describing a cut or a fit preference and attributing it to the cloth.
Cut is the real difference
Duluth cuts with noticeably more room through the seat and thigh. If your job involves crouching, kneeling or climbing - most trades - that extra room is the difference between a trouser you wear and a trouser that fights you.
Carhartt’s traditional fit is straighter and tighter through the thigh, which some people prefer and which is a genuine restriction for others. Carhartt’s relaxed and Rugged Flex lines address it in different ways - one with cut, one with elastane.
On a garment you will own for five years, that is not a minor consideration.
The warranty gap
Carhartt publishes a limited warranty covering defects in materials and workmanship, excluding normal wear and tear - including zippers and other hardware by name - and excluding misuse, neglect and alterations.
We could find no published warranty term for the specific Duluth product here.
In practice neither matters much, because neither covers the way work trousers actually end. Buy on fabric weight, construction and fit.
Construction details to compare on the rack
Double front. Carhartt’s B01 has it. It is the second layer over the knee that doubles the life of the trouser for anyone who kneels, and it can be re-patched repeatedly.
Gusseted crotch. The diamond panel that stops the four-seam split. Check for it on whatever you are buying.
Cleanout bottoms. Carhartt’s dungarees have an opening at the hem so you can take them off over boots. A small thing that matters daily.
The verdict
Carhartt if the fit works for you, because it is cheaper, more widely stocked and easier to replace with an identical pair in three years.
Duluth if Carhartt binds through the thigh and seat, which it does for a lot of people. Paying more for a trouser you can crouch in is not a premium, it is the point.
