A magnetic-core assembling tool may include first and second compression plate alignment guides configured to be respectively fitted to first and second compression plates of a magnetic-core assembly, a plurality of semiannular tension bars, and a clamping plate. The semiannular tension bars may be attached at a first end to the first compression plate alignment guide and at a second end to the clamping plate. The clamping plate may include a plurality of compression shoes configured to apply a variable amount of compression to the magnetic-core assembly. A method of assembling a magnetic-core assembly includes assembling a plurality of lamination stacks, staging the plurality of lamination stacks to provide a magnetic-core assembly, assembling a magnetic-core assembling-tool around the magnetic-core assembly, and injecting magnet retention adhesive into a plurality of magnet retention slots in the magnetic-core assembly housed in the magnetic-core assembling tool.