First: In the case of ductile materials like aluminum (Al-Si) or copper or stainless or cheap mild steel the tap is not just cutting but deforming too. Second: Most 'bricolage' work in the homeshop doesn't require the maximum / by-the-book strength of threads. Therefore tapping becomes easier (without sacrifying strength) if you increase the bore diameter:
M3-core ø2.46-bore ø2.6
M4-core ø3.24-bore ø3.5
M5-core ø4.13-bore ø4.4
M6-core ø4.92-bore ø5.2
M8-core ø6.65-bore ø7
M10-core ø8.38-bore ø8.7