This is a 25t shaft weight wag type bogie developed based on K4 bogie. The bogie is casting steel three parts wag bogie, which follows the main structure of K4, the spring plate is concave downward type modified from flat type of K4, the base braking adopts the L-c combined braking beam developed by the shop own, the shock absorber inter round spring, inclined wedge, flexible side support and other parts are mutually replaceable with K4.

Main technical parameters: 
 
Shaft weight/t   25
 
Deadweight   4.68 
 
Permitted load for center plate/t  45.5 
 
Maximum operation speed/km/h   120
 
Statistic flexibility of the spring/mm 
 
Unloaded car deadweight of the car body is 24t for calculation ≥18
 
Loaded car equivalent weight ≥40
 
Statistic spring flexibility difference between unloaded and loaded cars 
 
Fixed shaft distance/mm 1750 
 
Center distance of side support/mm 1520
 
Braking times 4 
 
Geometric passing through minimum collinear radius 100