620 series diesel engines include 620L6, 620V8, 620V12, 620V16. They were originally produced by Henan Diesel Engine Industry Co., Ltd (HND) in 1999 by introducing technology from DEUTZ-MWM Company in Germany. It is an improved and upgraded product of the 604B diesel engine. In 2019, HND independently developed an electronically controlled high-pressure common rail diesel engine. The bore/stroke of the 620 series diesel engine is 170/195mm, the power coverage is: 650-2240kW, and the speed range is: 1500-1800rpm. The mechanical pump diesel engine meets the Tier II and Tier III emission standard.

The 620 series diesel engine is widely used in the fields of ship main and auxiliary engines, civil ship main engines, generator sets, land-based power stations, oil drilling rigs, etc. due to its simple structure, superior performance, and easy use and maintenance.