What is Pipe Thread? The difference between a taper pipe thread and a pipe thread

The pipe thread is the thread used for pipe connection, which is inchal, generally expressed in inches by the inner diameter of the pipe, and the size of the thread is determined by the outer diameter of the standard pipe, and the external thread can be directly processed on the standard water pipe

Pipe thread: A thread located on the pipe wall for connection.

First, the reference is different.

1. Pipe thread: It is a thread located on the pipe wall for connection, with 55 degrees of unsealed pipe thread and 55 degree sealed pipe thread.

2. Cone pipe thread: also known as conical thread, mainly relies on the deformation of the tooth to ensure the tightness of the thread pair, and is mostly used for pipe fittings.

Second, the characteristics are different.

1. Pipe thread: Inch pipe thread** is the British Whitworth thread, and the combination of Wyeth thread pipe series and Wyeth thread tooth profile establishes the basic size of inch pipe thread. According to the 1 16 taper relationship, the radial diameter tolerance of the Whitworth thread is converted into the axial tooth tolerance of the inch seal pipe thread.

2. Cone pipe thread: without any filler, it can be sealed by direct screwing. Due to the taper, this type of thread has a "self-tightening effect" when mated with the same tapered or cylindrical thread; Its special tooth shape design has the characteristic of "perfect fit".

Third, the use is different.

1. Pipe thread: It is mainly used to connect the pipeline, so that the internal and external threads are closely matched, and there are two kinds of straight pipes and conical pipes.

2. Cone pipe thread: the raw material belt wound on the thread can be more evenly distributed on the thread, with better sealing, and the iron pipe wall used in the tapered pipe thread is thicker and has higher pressure resistance, so this kind of thread is commonly used to seal liquids and gases.

1. The 8 mark in the general pipe thread refers to the diameter of the thread size, and the unit is inches. Insiders usually use points to call the thread size, one inch is equal to 8 points, equal to the hidden wheel, 1 8 inches is 1 point, 1 4 inches is 2 points.

2. The pipe thread is the thread located on the pipe wall for connection, and there are 55 degree unsealed pipe threads and 55 degree sealed pipe threads. It mainly uses high carrying Hu to connect the pipeline, so that the internal and external threads are closely matched, and there are two kinds of straight pipes and conical pipes.

G1 - The nominal size of the bore is 1 inch, mm, and the outer diameter of the thread is 8 minutes;

The nominal size of the g1 2-inner hole is 1 2 inches, mm, and the outer diameter of the thread is mm, that is, 4 minutes;

The nominal size of the diameter of G1 4-inner hole is 1 4 inches, mm, and the outer diameter of the thread is mm, that is, 2 points;

The nominal diameter of the G3 4-inner bore is 3 4 inches, mm, and the outer diameter of the thread is 6 minutes.

Pipe threads are threads located on the pipe wall for connection, and are available in 55 degree unsealed pipe threads and 55 degree sealed pipe threads. It is mainly used to connect the pipeline, so that the internal and external threads are closely matched, and there are two kinds of straight pipes and cone pipes.

1 2-20 unf is a fine tooth thread made in the United States, 20 teeth per inch, other data are shown in the attached table. (The data in the table have been converted to metric system, unit: mm).

The size of the American thread is 7 16 smaller than 1 2, but its basic large diameter is only larger, and if the dimensional tolerance is considered, it seems that it cannot be 7 16 specification.

If the original thread does not have a taper (i.e., it is not a pipe thread), it is more likely to be 1 2 if it is worn for a long time.

The U.S. national thread profile (60 profile angle and h 8 leveling height) is different from the Wyeth thread profile (55 profile angle and h 6 leveling height). In the regions and industries affected by the U.S. industry, U.S. national threads are widely used.

In World War II, due to the inconsistent thread standards used by the Allied forces, logistical supply difficulties caused serious economic losses and personnel ** to the Allied forces. As soon as World War II ended, the United States, the United Kingdom, Canada and other allies immediately began to formulate a unified thread standard among the allies, and promulgated a unified thread standard in 1948.

Due to the dominance of the economic and military strength of the United States in the Allied forces at that time, the unified thread was mainly formulated according to the national thread standard of the United States, and the first letter "u" of the unified thread code "un" was "unified" among the allies; The last letter "n" is derived from the code "n" for the national thread of the United States. Since then, the unified thread has begun to squeeze the original use market of Wyeth thread in the UK.

Pipe threads: Pipe threads are threads located on the pipe wall for connection, and are available in 55 degree unsealed pipe threads and 55 degree sealed pipe threads. It is mainly used to connect the pipeline, so that the internal and external threads are tightly matched, and there are two kinds of straight pipes and conical pipes.

Ordinary thread: An ordinary thread is a spiral shape made on the surface of a cylinder or conical matrix with a specific cross-section, continuous convex section.

Expand

In machining, the thread is cut with a tool or grinding wheel on a cylindrical shaft (or the surface of the inner hole), at this time, the workpiece rotates, the tool moves a certain distance along the workpiece axis, and the traces cut by the tool on the workpiece are threads. The thread formed on the outer surface is called the external thread. The snail pattern formed on the surface of the inner hole is called the internal thread slap.

The basis of the thread is the helix on the surface of the round shaft. Usually if the cross-section of the thread is triangular, it is called a triangular thread; The cross-section is trapezoidal, called trapezoidal thread; The cross-section is zigzag, which is called a zigzag thread; The cross-section is square, which is called a square thread; The cross-section is arc-shaped, called arc-shaped thread, and so on.

Pipe thread is the thread on various pipes, such as water pipes, gas pipes, waste pipes, etc., pipe threads are generally well sealed, which can prevent leakage of various liquids.