Abstract: A manual rotary-shear cutter for severing sheet metal stock has a cutting head and a handle joined by an extension tube engageable with and selectively retained at sites formed on the cutting head and handle. A series of preformed apertures spaced along the extension tube allows shortening of the overall length of the cutter by severing the extension tube and aligning the apertures nearest the end of the extension tube with passages formed at such sites, inserting fasteners therethrough, and releasably securing such fasteners. A connecting sleeve may also be provided to join individual extension tube segments, thereby forming a longer extension. Flanges formed integrally with the head define mounting sites for the cutting blades, and overlap the blade edges, to protect the cutting edges of the blades.