The whole "hole is 2-3mm bigger than the bolt, the world is going to end" malarkey is a right laugh. Standard industry-wide (I'm talking all industry here, from cars to mining to construction) clearance hole for a bolt is generally ~2mm larger in diameter, so an M10 bolt goes into a 12mm hole, M16 into an 18mm hole, M24 into a 26mm hole etc and so on. Bolts generate clamping force and are strong in tensile loading, they are not designed to have shear loads placed on them (especially not on the threads), thus the holes have to be oversize, and why torque values are important (because the torque value is what generates the clamping force, which in turn generates the frictional force which resists shear loadings.