Abstract: A coupling structure for a split boom power tool is provided. The structure permits any of a variety of lower tubular boom members with their working tools to be quickly and easily coupled to or uncoupled from an upper tubular boom member having a power source. The structure includes compatibly sized end portions on the upper and lower boom members that allow them to be quickly and easily telescopically joined and also provide a strengthened joint. A clamping member is provided with a locating tab that is receivable in a locating hole in the tube of the upper boom member to allow the clamp to be quickly and positively positioned at the joint. A plurality of tool orienting openings are provided in the end portion of the upper boom member and clamp to receive a spring loaded locking pin carried in the lower boom member to position the tool at a desired angular working orientation.