Advice 1: How to thread

When repairing furniture and various household things in the course of work, often need the connection details of construction by means of threaded connections. The cutting quality of carving in the home, time-consuming and requires skills, but this problem is solved.
How to thread
You will need
  • You'll need: a vise, a file, taps, dies, tap wrenches, machine oil and desire.
Thread is, in essence, a spiral groove cut on an outer or inner cylindrical surface. Mainly used to connect different parts with each other. In engineering can be used to convert translational motion into rotary and Vice versa. There are two types of threads such as metric, with the profile angle 60o and pipe with angle 55о.
In a metric thread diameter and thread pitch measurements are in millimeters. In the designation of a metric thread is used alphabetical and numeric labelling, such as M8x1. 5. The number eight corresponds to the thread diameter, and 1.5 indicates the thread pitch, the distance between turns.
In inch thread, the measurements are conducted in inches and the number of turns per inch. One inch is equal to 2.54 cm To the inch example thread record 1 1/4".
Cutting external threads.
To cut external threads you need to take a die of desired size to prepare the workpiece, and in particular, to pick up a workpiece of a particular diameter. The diameter of the workpiece for threading is determined by the tables. In practice, for cutting, for example, a thread diameter of M6, required rod cross-section of 5.92 mm, that is approximately one-tenth of a millimeter smaller for the thread M8, the workpiece should have a diameter of 7.9 mm.
Here's an example excerpt from the table of diameters for metric threads:

Thread diameter/shaft diameter (mm) - 5/4,92; 6/5,92; 8/7,9; 10/9,9; 12/11,88; 16/15,88; 20/19,86; 24/23,86
After the selection of the workpiece, it is clamped in a vise, a file is removed from the end of the chamfer for proper setting of the dies, and rotary-clamping movements and threading do not forget to lubricate the part with engine oil.
Dies for cutting external threads.
The internal thread is cut by the tap. Pre-drilled holes must be smaller in diameter, you need thread. Extract from the table of diameters of drill bits for drilling holes are shown below.

Thread diameter/hole diameter (mm) - 2/1,6; 3/2,5; 4/3,3; 5/4,2; 6/5,0; 8/6,7; 10/8,4; 12/10,2; 16/13,9; 20/17,4; 24/20,9
For threading inside the part, you must have two of the tap, roughing and finishing.

Also hold the detail in cutting and rotational movements with slight pressure threaded tap draft, periodically lubricating the tap with engine oil, then make a finishing pass. Thread ready to use.
Taps for internal threading.
For more quality threads do turn of a knob 180 ° clockwise and then 90°. Due to this cut long chips and decreases the force on the knob.

Advice 2 : How to draw a thread

During the technical drawing quite often have to deal with the image of standard fasteners. Many of them have a threadthat we have to draw a picture. The main parameters of the thread are external and internal diameters, as well as step.
How to draw a thread
You will need
  • - a sheet of paper;
  • a pair of compasses;
  • - the range;
  • pencil
  • - table of standards for bolts.
Select the external diameter of the thread. In technical documentation it is usually denoted as d without an index. It is equal to the diameter of the cylinder, which is applied to the thread. Inner diameter is d1. Important and length of the cylindrical part, and the size of the plot, which is applied to the thread.
Depicted on the plane of the cylinder looks like a rectangle. Draw the cylindrical part of the bolt. Details width equal to the diameter of the cylinder, and the length corresponds to the length of the part. Draw a middle line, dividing in half the short side of the rectangle.
On the long sides from one end put the thread length. Put points and connect them by a thin line. From the point of its intersection with the middle line put in both sides of the size equal to half the internal diameter. Do the same on the short side, which is the beginning of the thread. Connect pairwise the points obtained thin lines. The drawing must specify both the diameter of the thread.
This method is used when drawing projections, which have fasteners visible cylindrical rod. Other projections can be depicted, for example, the head of the bolt or screw. Draw a hat of the desired shape, and then determine its center. Put in this point the needle of a compass and draw a circle whose radius is equal to the outer radius of the thread. Do a second circle of the same center. Its diameter should be equal to the inner diameter of the thread, which is indicated by a thin line. In the drawing, both the insert diameter. The line drawn inner circle is usually not closed.
The thread can be internal. Draw the opening on the respective projection parts. As in the first case, on some projections it will look as a rectangle, other times as a circle. The thread just has two diameters, the inner will be more external. Draw a cylindrical hole in the shape of a rectangle. Its width corresponds to the outer diameter of the thread. Swipe the middle line in the same way as in the first method. From the intersection points put in both sides of the size of the inner radius. The same periods of put and the beginning of the thread. Connect pairs of dots with a thin line.
On the projection where the hole should look like a circle, draw a circle of appropriate diameter and draw a circle around it. From the same centre sweep a thin line of a second circle whose radius is equal to the internal radius of the thread.
Learn to read the labels. It consists of letters and several digits. The letter denotes the thread. For example, M — metric thread. This is followed by the designation inner diameter. A major step is not indicated, and the size small is put after the "x" icon. Left thread is marked with the letters LH.
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