Hello motorcycle friends, on the housing (the housing is made of cast iron. the screws are made of anodized steel) of my clutch switch is the screws depleted and so I took the drill and wanted to drill the screws out. the screws is however so hard that I can barely get one mm further. the hole is now about 3-4 mm deep. then I set a left turner and tried to turn the screws out but the grips at all. I use hss drills from the building house. the best loud salesman. the drills break off after the row. I cool them and also tried to try out different strengths but nothing goes on. I thought about getting titanium drills and drilling a hole at least as deep as that the left-hand turner takes hold. slowly the ideas go out, maybe you have a refined idea? by the way, I have attached a picture. at the bottom right is the exhausted hole to see! mfg jan