Like Frosty said, they are pretty much the same thing. Now, there IS a substantial difference, however in the earlier models vs. the later ones in both brands. The early Hay Buddens and Trentons aren't bad anvils by any means, but they are kinda your regular anvil, like a Peter Wright. Wrought iron body, steel face. In 1908, Hay Budden (and Trenton, shortly after) started making their anvils with tool steel from the waist up. Trenton had the idea of casting the bases to lower the cost, and Hay Buddens tend to have a slightly better finish (where it doesn't matter for functionality) , so a Hay Budden might be kinda like a Trenton with a gold trigger.