G'day folks,
Just a FYI, for before you deploy these hammer type impact drivers.
Setting a flat ended punch on the screw head, and giving it a few smart smacks with a lightish hammer, can help to break the corrosion bond between screw and alloy. Use a heavy hammer on the driver, though.
This type of impact driver was an essential service tool, when working on 1970s Japanese motorcycles - my example dates from that era.
These bikes had a lot of M6x1.0 Philips head screws holding their crankcases together, and the screw heads were quite soft. Only these impact drivers could get those screws out.
It was so big a problem, that the motorcycle trade then offered model-specific kits of plated Allen type socket head cap screws, to replace the originals!
Another good tip is, that when reinstalling steel screws into alloy, use a low strength thread locking compound [e.g. Loctite 222] - that prevents the corrosion bonding.
