Description

The Cummins Steel Insert Piston Assembly M-6050-50 (0.50 mm Oversize) is a heavy-duty replacement piston engineered for diesel engines that have undergone light cylinder boring during professional rebuilds. Featuring a steel insert piston design , this assembly directly replaces Cummins OE part number 3942564 , ensuring OEM-accurate fitment, correct compression height, and reliable combustion performance. Designed for Cummins diesel engines , the steel insert construction combines the lightweight benefits of aluminum with reinforced steel in high-load areas. This design improves resistance to heat-related fatigue, minimizes piston distortion under high cylinder pressures, and extends service life in demanding diesel applications. The 0.50 mm oversize specification restores proper piston-to-cylinder clearance in bored cylinders, helping maintain compression, oil control, and overall engine efficiency. Precision-machined ring lands, an optimized skirt profile, and balanced geometry reduce friction, control thermal expansion, and support smooth piston operation. The Cummins M-6050-50 steel insert piston is commonly installed during in-frame overhauls, full engine rebuilds, and professional remanufacturing projects . It is trusted by diesel technicians, fleet maintenance teams, and engine builders seeking OEM-style performance with enhanced durability.