Disclosed are fittings (e.g. tub spouts) suitable for mounting to a member (e.g. a water pipe). Special clamping structures are provided and located in a cavity of a fitting body. The clamping structures have at least two separate clamp parts that surround the water pipe or other member. A set screw can be extended radially inward from a hole in the fitting body to drive a clamp part. This helps to retain the end of the member in the cavity, while distributing clamping load away from a single point.