Question: Which city is famous for its ball bearing industry, Wafangdian or Tumen, Jilin?
Context: Sven Gustaf Wingqvist (10 December 1876 – 17 April 1953) was a Swedish engineer, inventor and industrialist, and one of the founders of Svenska Kullagerfabriken (SKF), one of the world's leading ball bearing and roller bearing makers.  Sven Wingqvist invented the multi-row self-aligning ball bearing in 1907. Tumen is a county-level city in Yanbian Korean Autonomous Prefecture, eastern Jilin province, Northeast China.  Of its 136,000 inhabitants, approximately 78,000 (or 57%) are of Korean descent.  The two official languages are Chinese and Korean.  Tumen is separated from Namyang of North Hamgyong province of North Korea by the Tumen River.  Due to this proximity, many North Koreans escaping their country pass through Tumen.  Tumen is also the location of a large detention center for captured North Koreans awaiting deportation.  Tumen has two major food markets, the South Market and the North Market, where most of the residents purchase their food.  Packaged foods and meats are usually sold inside the building, and vegetables are sold outside.  There are six elementary schools, with three Korean schools, and three Chinese schools. Wafangdian (), formerly Fuxian or Fu County (), is one of the two "northern county-level cities", the other being Zhuanghe, under the administration of Dalian, located in the south of Liaoning province, China.  The city is famous for its ball bearing industry.  Wafangdian Bearing Factory is the largest bearing manufacturer in Asia and was initially built by the Japanese during World War II.  Its area is 3576.40 km² and its permanent population as of 2010 is 942,197, compared to 1,024,876 registered with hukou permits.  The city borders the prefecture-level city of Yingkou to the northeast. Frelon is a polytetrafluoroethylene (PTFE) based material with other proprietary fillers to increase bearing characteristics, such as low wear, low friction, and high strength.  It is chemically inert and self lubricating.  It qualifies as a class III plain bearing.  The load capacity of a frelon-lined bearing is typically four to eight times that of a comparable ball bearing; for instance, a 0.5 in Frelon-lined bearing can support the same load as a 1 in ball bearing. The Tumen River Bridge () is a bridge over the Tumen River, connecting Hunchun City, Jilin Province, China, with Undok County, North Hamgyong Province, North Korea.  It was built in 1938 by the Japanese Empire and is 535.2 m long and 6.6 m wide.  It is located at Quanhe where the Quan River meets the Tumen River. The Tumen Border Bridge () is a bridge over the Tumen River, connecting Tumen City, Jilin Province, China, with Onsong County (Namyang), North Hamgyong Province, North Korea.  It was built in 1941 by the Japanese and is 515 metres long, 6 metres high, 6 metres wide.  Tumen Border Post is located there.  A little upstream from the bridge is Tumen Border Railway Bridge. Ball Bearing was a 1992 television advertisement for the Lexus ES 300, which introduced the luxury sedan to American television audiences.  It was created by Team One, a unit of Saatchi & Saatchi.  The advertisement showed a ball bearing rolling smoothly down the panel seams of a Lexus sedan, thus demonstrating the precise quality of its exterior elements.  The television spot won awards, was emulated by subsequent commercials, and was credited for focusing industry attention on body tolerances. The ABEC scale is an industry accepted standard for the tolerances of a ball bearing.  It was developed by the Annular Bearing Engineering Committee (ABEC) of the American Bearing Manufacturers Association (ABMA).  The ABEC scale is designed to provide bearing manufacturers dimensional specifications that meet the standards of precision bearings in a specified class.  Manufacturers who produce equipment that require bearings must also know the dimensional tolerances to design parts that will accommodate a bearing. The Gaya River () is a tributary of the Tumen River in east Jilin province of China.  The source of river is located in Wangqing County and flows generally from north to south and joins Tumen River at Tumen City. The river has a length of 205.2 km and drains an area of 13,565 square km. A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.
Answer: Wafangdian Bearing Factory is the largest bearing manufacturer in Asia