Which company's products are the trains in Beijing subway?

Changchun Bus Factory (now CNR Changchun Rail Bus Co., Ltd.)

Representative models: DK3 (scrapped), DK 16 (scrapped), DK20 (scrapped), DKZ4, DKZ5, DKZ 16, etc.

Beijing Metro Vehicle Factory (now called Beijing Metro Vehicle Equipment Company)

Representative models: partial orders for BD2 (scrapped), subcontracted DKZ4, DKZ5, DKZ 13 and other models.

The train of CSR Qingdao Sifang Locomotive & Rolling Stock Co., Ltd.

Representative models: SFM0 1, SFM02, SFM0, etc.

In terms of vehicle quality, long-distance passengers are the best, Beijing Metro Vehicle Factory is the worst, and the square is average.