The ten Pacifics of class K-6 entered service on the Boston & Albany in 1925 and 1926 as Nos. 590-599. No. 595, seen in this builder's photo from American Locomotive Company's Brooks Works, was a member of the second group in class K-6b. These 4-6-2s had 75-inch drivers and 26x28-inch cylinders, and weighed 298,000 pounds. They had a boiler pressure of 200 pounds per square inch and produced 42,900 pounds of tractive force, with a booster supplying 9,720 additional pounds. They had 4190 square feet of evaporative heating surface and 1165 square feet of superheater surface, with a grate area totaling 68 square feet. In 1931, with delivery of the J-2 Hudsons to the B&A, the K-5s were transferred to the Pittsburgh & Lake Erie (see P&LE No. 9247 below). No. 595 became P&LE No. 9250, and was retired in 1950.