A 45# honed tube is a high-precision, cold-drawn seamless steel tube manufactured from 45# grade carbon steel (AISI 1045) and subsequently finished with an internal honing process. This specialized manufacturing sequence transforms a standard seamless tube into a critical component designed for applications demanding exceptional dimensional accuracy, superior surface finish, and outstanding mechanical properties. Primarily serving as the cylinder barrel in hydraulic and pneumatic systems, the 45# honed tube is the foundation upon which reliable, efficient, and long-lasting linear actuators are built.