The qualities that make aluminium lightweight create problems when you are creating a threaded hole in the material. Drill bit and taps used on aluminium will clog as they remove material from the area. Each tool will fail to cut the aluminium once clogged. Keeping the tools free of aluminium ensures a threaded hole able to hold a fastener.
Reference a tap chart to determine the drill bit size required for the threaded hole.
Secure the drill bit in a drill motor. Cover the end of the drill bit and the surface of the aluminium with cutting fluid.
Place the point of the coated drill bit on the aluminium. Pump the trigger of the drill motor to drill into the metal. Apply additional cutting fluid to the aluminium as you drill.
Secure a tap in the handle of a tee-handle tap wrench. Apply cutting fluid to the threads of the tap. Pour cutting fluid into the drilled hole.
Turn the tap handle clockwise to thread the tap into the hole. Reverse the direction of the tap when you have difficulty turning the tap into the aluminium.
Remove the tap from the threaded aluminium hole. Run a wire brush around the threads of the tap.
Thread the clean tap back through the threaded hole.