Description

The Cummins Steel Crown Piston M-4860 (Standard Size) is a heavy-duty piston assembly engineered to handle high combustion pressures and extreme operating temperatures in Cummins diesel engines . Designed as a direct replacement for OE piston numbers 5258754 and 5258755 , this piston delivers OEM-level durability, precise fitment, and long service life. Steel crown pistons are specifically designed for modern, high-output diesel engines where thermal load and cylinder pressure exceed the limits of conventional aluminum pistons. The steel crown construction improves resistance to cracking, reduces crown deformation, and supports higher combustion temperatures, making it ideal for turbocharged and common-rail diesel applications. The M-4860 piston features precision-machined ring lands, controlled expansion geometry, and an optimized skirt design to maintain piston stability, reduce friction, and support consistent combustion. When paired with the correct piston rings, pin, and retainers, this piston helps restore factory compression, minimize blow-by, and control oil consumption. This piston is commonly installed during engine rebuilds, in-frame overhauls, piston replacements, and professional remanufacturing projects . It is trusted by diesel technicians, fleet maintenance teams, and engine builders who require OEM-equivalent strength and reliability. Cross-Reference (OEM) OE Piston Numbers: 5258754, 5258755 Aftermarket Reference: M-4860 Size: Standard (STD)