INDIANAPOLIS—President Donald Trump boosted the hopes of employees at Rexnord Corp.’s factory here in December when he castigated the company for “viciously firing” workers and planning to move their jobs to Mexico.

Two months later, Rexnord is still planning to close the industrial-bearings factory, which employs about 350 people, despite Mr. Trump’s shaming and his earlier intervention to stop a nearby Carrier Corp. furnace factory from closing.

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