work of the nuts easier. The number of different types and sizes of machine screws, nuts & bolts prohibit the possibility of introducing them all here so the following information addressed the elementary information only. Screw tapping includes thread, which help them to form the grip, cut, and fit on the surface easily. This thread comes in different variety and choices.

Tapping: Types of Threads
The threads used for tapping purpose are triangle shaped threads. Moreover, square shaped and trapezoid shaped threads are used moving machinery, which need high accuracy, such as a lathe. In respect to thread standards, there are a metric thread (M), a parallel thread for piping (PF), a taper thread for piping (PT), and an unified thread (UNC, UNF). The following information is related metric threads, because they are the most widely used in Japan and many countries around the world..

Terms of tread for napping
The main use of these screws to mate parts and make it fix to the surface. napping includes thread cutting process where there are extensive usage of screw and clearance hole in pieces . So for the work purpose these two pieces are joined together using screws, one piece is made with threads, and another piece is made with clearance holes, which have bigger diameters than that of the screws. If the diameter of the clearance hole is too small, the piece cannot be assembled, as the screw will not fit through the hole. In addition, if the diameter of the clearance hole is too big, The piece will be loose as the hole will provide a sloppy fit. Therefore, we must provide make suitable diameter clearance holes. As a "rule of thumb", the diameter of the clearance hole has more 10 % than the diameter of the screw. For examples, the clearance hole for a M3 screw has 3.2 mm or 3.5 mm diameter. The clearance hole for a M4 screw has 4.2 mm or 4.5 of diameter. In addition, we would make a hole with 5.5 mm of diameter for a M5 screw.

Caution while using the thread for napping
When we the tread for napping purpose we need to take care, so here are the following thing, which we have to take in consideration.
(1) Start the thread with a perpendicular positioning of the tap or the die.
(2) Turn the tap or die in quarter turns and "back off" quarter turns to remove melat chips so that they do not clog the tool.
(3) Always use cutting oil.

Clutch screwdriver bit:
The screwdriver should fill the screw slot or head completely or come within 1/16" of doing so. If the tip is too small, the driver will not have enough bite to turn the screw and will slip, stripping the head. If the tip is too large, it will not...

Screw Machine Shop:
The specially of these screw making shops is that they specialize in precision machining and finish grinding of custom cylindrical components, ranging from miniature heat-treated pins for the bearing industry to large drive shafts for paper feeding...

Socket head cap screw dimensions:
A screw is a shaft with a helical groove or thread formed on its surface. Its main uses are as a threaded fastener used to hold objects together, and as a simple machine used to translate torque into linear force. It can also be defined as an...