Why slotted screws have still been used since the invention of the Allen screw (or at the latest since the market launch of the Torx screw) is written on the tombstone of the unknown engineer.
At best, the car or motorcycle factory probably saves 20 euros – per million vehicles with such a design. Conversely, it makes life difficult for almost exactly one million mechanics 20 years later to move these penny parts. This is because it is often not the thread that bogs down, but the tapered head. The fact that the steel screw is even stuck in light metal makes things both bad and annoying.
In this case, the last resort before a rampage in the nearby kindergarten is a courageous blow with a center punch. However, the special tool used for this purpose should not be freshly sharpened and razor-sharp, but somewhat round and worn. Otherwise, a fresh center punch will bite too deeply into the material – and you won’t win anything.
It goes without saying that the round center punch is placed quite far out. And now: hold your breath – hit it – hit it again – HOORAY!
Countersunk head in light metal – you wouldn’t think the Japanese could commit such a crime.