Varieties of metizes

Practically no type of construction work costs metered materials. Meanwhile, we know very little about such a trifle like self -tapping. It would seem that you think that there is such an ordinary screw. Ordinary and not ordinary.

Screws and samarezes are completely different types of material. The self -tapping screws themselves are divided into two categories:

on metal

On wood.

Self -tapping screws for metal, unlike wood screws, have a small thread step. If it is wrapped in a tree, he, of course, will hold on, but more poorly. It depends on the fact that the small thread during twisting practically cuts the entire wood . Therefore, each species should be used for its purpose. Metal screws can be equipped at the end with a small drill, this allows you to use them without preliminary drilling the hole . If you noticed, on long wood screws, the thread does not reach the end, this is not done at all out of savings. When connecting two wooden parts, having found himself in the hole, that part of the self -tapping screw that is without a thread, being more thin, can freely move along it. Thus, it presses the upper part of the part more tightly and makes the connection denser and more reliable.