Abstract: A winding core has high stiffness by virtue of being formed predominantly of fiber-reinforced plastic (FRP) such as fiber glass material or the like. In particular, the winding core comprises a tubular shell of FRP, and a pair of generally tubular end fittings bonded to the inner surface of the shell at the opposite ends, the end fittings comprising a material having a durometer hardness substantially lower than that of the shell and being positioned to be engaged by wind/unwind chucks. Each end fitting has an axial length that is a relatively small fraction of the length of the shell.

Abstract: A stackable winding core in accordance with the invention has a male end and an opposite female end. The ends are configured in such a manner that they do not hinder or prevent the insertion of chucks or mandrels into the core for winding or unwinding of web material about the core. The male end of one core is receivable into the female end of another core so that the cores can be axially stacked end-to-end, the engagement between the ends of the cores keeping the core coaxially aligned with each other. The ends are also configured to support axial loads exerted between the cores.