The 4 June Rolling Stock Works (Korean: 6·4차량종합기업소, 6.4 Ch'aryang Chonghap Kiŏpso) is a manufacturer of railway rolling stock in Wŏnsan, North Korea.
It is capable of producing 3,000 new freight cars per year, as well as repairing 200 steam locomotives and 130 buses.
[1] The plant was originally built in the colonial era, specialising in the production of parts for rolling stock and undertaking minor locomotive repairs.
[2] The first trial of an all-steel gondola of 60 tons capacity took place in 1959, with mass production of the design commencing in 1966.
Production of the Type 551 boxcar began on 10 May 1963,[2] and in 1982, a new four-bogie gondola of 100 tons capacity (Mu12 class, Korean State Railway 48000-series) and cleared for 90 km/h service, was introduced,[3] entering production in 1987.