Upgrade your precision machinery with these uxcell Linear Motion Rod Shafts! This pack includes 4 rods, each measuring 8mm in diameter and 100mm (about 3.94 inches) in length. Made from C45 carbon steel that's case hardened and chrome plated, they offer excellent hardness (58-64 HRC), corrosion resistance, and durability. The straightness is super precise – under 0.1/1000mm – which is crucial for smooth, accurate linear movement. These rods are designed to work with linear bearings, support blocks, or enclosed sliders in applications like 3D printers, CNC machines, engravers, routers, robotics, automation equipment, and other industrial tools. They help reduce friction and ensure stable, repeatable motion. Easy to install and a cost-effective way to replace worn-out rods or build your own DIY projects. Whether you're a hobbyist, maker, or professional, these high-quality guide shafts are a reliable component for your mechanical setups.