Mechanics need this tool!

How do mechanics lock heavy engine valve springs into place?! ⚙️🔧
Inside a cylinder head, the engine valves snap open and close thousands of times a minute to let air and exhaust flow through the combustion chamber. To snap these valves shut so quickly, they rely on heavy-duty coil springs that are under hundreds of pounds of constant tension. But how do you attach a heavy spring to a perfectly smooth metal valve stem without it slipping off?
Enter the valve keeper! Using a specialized compression tool, the mechanic forces the heavy spring downward, exposing the grooved top of the valve stem. They then carefully place two tiny, wedge-shaped metal pieces—called keepers or collets—around the groove. When the compression tool is released, the spring pushes upward against the wedge, locking the entire assembly tightly together! Because of the tapered design, the harder the spring pushes, the tighter the grip becomes!