Two bank robbers — one in a FedEx uniform, the other in a dapper blazer — made off with $400,000 last night from a Long Island Chase branch, cops said.

They got to the East Rockaway branch at 6:18 p.m., waved their guns, tied up three workers, stuffed a duffel bag with cash from a vault and got away in the bank manager’s Infiniti sedan before abandoning it nearby.

The one in the blazer was dressed in a way resembling Chase managers, investigators noted.