Dana Spicer's chromoly axle shafts, which are designed for larger tires, are manufactured using SAE-4340 nickel chromoly steel for maximum strength and durability and are heat-treated to ensure optimal hardness.
The Spicer axle shafts are made entirely from SAE-4340 nickel chromoly steel for ideal hardness throughout the structure. The nickel provides additional toughness, while the chromium ensures high-temperature strength and resistance to abrasion. Dana also adds molybdenum to maintain a specified hardenability.
Heat-treatment processes developed for the Spicer chromoly axle shafts are designed to increase core hardness to precise levels, while at the same time optimizing case and surface hardness to achieve maximum impact strength and durability.