A fin and tube heat exchanger includes a plurality of heat transfer tubes arranged in parallel and a plurality of plate-shaped fins provided orthogonally to the heat transfer tubes, each of the heat transfer tubes is in contact with fin collars of the plate-shaped fins and is inserted along the fin collars. Each fin collar is configured to include a bend in each of a re-flared portion and in a root portion of the fin collar. A thickness of the re-flared portion is smaller than a thickness of the root portion and a radius of the bend of the re-flared portion is larger than a radius of the bend of the root portion.