This is an economical spiral-flute M5 x 0.8 mm tap. It is designed specially for aluminium alloys. It is made of high-speed steel (HSS), which is much more resilient than the brittle carbon steel normally used for inexpensive hand taps. It has wide flutes for easy chip removal. It is coated to reduce friction, but a lubricant is still necessary. For tapping just a few holes at a time, any oily substance will do (including baby oil and WD40). Tap carefully, using a tap handle and holding the tap aligned with the hole. After every two or three turns, back out half a turn to break the chips. If it becomes hard to advance the tap, do not force it; back out completely and clean the tap (e.g. with an old toothbrush), and re-apply lubricant. Also clean the tap after each hole. It is possible to tap with a cordless drill, but it requires a certain amount of skill. If using a drill, always clamp the part to the table, and hold the drill with two hands to stabilize it and avoid off-axis forces that can break the tap.