A knock-down shelving unit is composed of four identical short panels, each having a slot extending perpendicularly from the middle of one edge to an inner end half way across the panel, and at least four longer panels, each having three similar slots. The optical storage apparatus includes a pickup head, a preamplifier, and a servo control. The assembling portion defines a number of positioning holes corresponding to the optical fibers in position. Certain collars of different materials have similar outside diameters for installation by a tool having a swage anvil with a uniform swage cavity that swages the collars into the lock grooves for securing workpieces in shear, sheartension, shear composite and sheartension composite applications.