A triangular groove on a system of measures is divided by a metric and dyuymouyu. Thread having a profile view of an equilateral triangle with an apex angle equal to 60 , called the metric. It is used in instrumentation and engineering. The outer diameter of the screw or the inner diameter of the holes with metric thread is measured in millimeters, and the pitch millimeters and fractions of a millimeter. Inch thread has the same profile form as the metric, but the apex angle is 55 .
It differs from a metric thread a big step, measured in inches. When assembling plumbing parts used inch thread. Inch thread is mounting and pipe. Mounting thread differs from pipe in that it has a big step, gives a strong connection, is used for cutting bolts, nuts, rods and holes. Pipe thread used to connect pipes. It is smaller mounting, as the depth of its limited thickness of the pipe walls.
Due to the large number of threads per one inch length of cut pipe thread density is much more fixing. Screw mounting thread by hand Screw the male thread. Male threads on bolts, screws and rods are hand-cut dies. Depending on your plate are prismatic, sliding, solid round prismatic plates consist of two identical halves, which reinforces the die stock having the shape of a frame with handles. On the two outer sides of these plates are prismatic grooves, which include prismatic protrusions die stock. Sliding plate set in the die stock so that the numbers / and 2 halves of the dice were against the corresponding numbers marked on the frame. Otherwise, the thread will be incorrect. Fixed plate stop screw. Between persistent screw and plate steel plate is placed, a biscuit, so that when pressed, screw die not burst. Circular plate-reinforcing in vorotke lerkoderzhatele (46 g) with two or four stubborn screws. To obtain the correct thread necessary that the diameter of the rods and drilled holes corresponded to the size of the thread. Sliding rams as well as with the threading of the machine can cut a full thread with small deviations diameter rod. When threading round dies are not allowed one piece of deviation in diameter of the rod being cut. In the larger diameter of the rod thread is smooth, with a smaller – incomplete. Bolts when cutting Thread strengthen vertically in a vise. Sliding dies cut the threads in two or three passes, and circular – 'one pass'.