Most, if not all, the manufacturers make at least 3 grades of rotary cutters; light, medium, and heavy duty, so you just need to be sure you're getting the right one for what you want to do. Naturally, as you got up from light to medium to heavy duty, the price goes up also. Just as one example: the Bush Hog Squealer series is light duty, rated to cut material up to 1", while the Bush Hog Model 406 is their heavy duty model, rated to cut material up to 4". Now for "occasional" use, you can probably get away with cutting more than the machine is rated for. As one example: when the dealer delivered my cousin's Bush Hog squealer, he promptly drove right through a grove of saplings that were 2" to 3" thick with a machine rated for only 1". Frankly I thought he might damage it, but after he left, I inspected the bottom side of that machine and found no damage. I still would not recommend over doing it that much.