This auger drill bit will start to cut into buried stand stone rocks and then stop after the tip is in the rock, spinning in the hole the tip cored into the rock. This acts more like a drill bit than an auger— the wide center shaft pushes into the ground but the narrow spiral auger path does not pull much dirt out of the ground. So it is good if you want clean holes without mounds of dirt by them. I also have a different auger bit that is the same diameter but has a thin 3/8” center shaft, and it makes large mounds of dirt around the hole, excavating the material. This goes deeper and will take on rocks, but it does not lift small rocks out of the hole, it pushes them aside. I tested this in sandy gravel soil, and clay soil. This may be better for clay soil because it breaks up the soil into fine powder more than the small-shaft bit that pulls clay out in large chunks. Seems sturdy. Remember SDS plus is backwards-compatible with SDS. This seems like it will last longer than my thin-shaft auger because it has a replaceable SDS+ adapter, whereas the other thin-shaft auger bit now has a rounded shank. If you don’t need overburden to push back in the hole, this is good. For vertical mulching, I have to bring in backfill for the holes when I use this auger.