When you open up a vintage IBM Beamspring keyboard you often find rusty springs. Using them in this state creates metallic dust, which gets inside the switches and makes them scratchy. Removing the rust is a frustrating job and requires treating the springs afterwards to prevent them from getting rusty again.
Another option is to replace the springs entirely. These ones are custom-made to match original feel and dimensions, and gold-plated for ultimate rust prevention.
Each order comes with 88 springs.