NONOX World

Screws hold together the greater part of the man-made world, and the most striking difference between them shows itself in their head design. Hex-head bolts, cylindrical head hex socket screws, headless screws and grub screws, countersunk, raised countersunk and “D” head screws.

Some sell screws by the piece, some by the kilo. Threaded rod, however, is customarily asked for by the metre. Economical cutting, cut-to-size ordering, trapezoidal threads, welding, galling - and why the stainless version's 700 N/mm2 beats the traditional 4.6.

Whether civilisations unknown to us exist is not a question for me. Where there are components, they must be fixed to one another - so screws must exist elsewhere too. But on the Moon there is no industry yet: everything has to be taken from here, from Earth.

The diameter of the pre-drilling always falls between the core diameter and the nominal diameter of the screw. Sheet thickness, sheet material and the drilling technology all shift it. Always carry out a trial before beginning mass production.

Man created the screw, and with it the problem. Security screws can only be fitted with a special purpose-made tool. Snake-eye, pin Torx, triangle-head, McGard and one-way screws, security nuts - and the cheapest security screw of all, the carriage bolt.

The suction effect of the wind can reach 4-5 times the dead weight of the roofing material. The storm clip costs about as much as the tile itself; nailing holds only the top third. The tinsmith's screw is simple, cheap and the most aesthetic solution.