Hebei Qierjie New Energy Technology Co.,Ltd, professional manufacturer for Seismic Bracing products, Thread Rod Galvanized, the main parts for seismic bracing project during building construction installation.

Commonly used screw threads we are divided into: triangle thread, trapezoidal thread, rectangular thread, serrated thread, ball thread.

1. Triangle screw

Let’s say M, for example, M5, M5. The triangle screw is also divided into coarse teeth and fine teeth. The Angle of the triangle teeth is 60°, and the tooth shape is like a triangle and the top is pointed. Generally, those without marks are by default coarse teeth, and those needing special fine teeth should be marked with tooth spacing. For example, the M6*1.25 triangular teeth are the most commonly used teeth. For example, the screws we commonly use are triangular teeth, which are convenient to process and simple to make. There are usually standard pieces for sale on the market.

2. Trapezoidal teeth

Let’s use T, for example, T30*6, where 30 is the outside diameter and 6 is the tooth pitch. The Angle of trapezoidal teeth is 30°, and the Angle of imperial teeth is 29°. The tooth shape is like an isosceles trapezoid, narrow at the top and wide at the bottom. The trapezoidal teeth are relatively simple to process, and the tightness of the nut and screw can be adjusted according to the depth of the teeth. Internal and external thread is not easy to loose with conical surface, good process, high root strength, good for neutral. Mainly used for driving thread.

3. Rectangular teeth

Also expressed in terms of outside diameter and pitch. “Tooth shape is square, tooth shape is 0 degrees.” There is no national standard for this thread; Thread thickness equal to 1/2 pitch. Drive. High transmission efficiency, but low alignment accuracy, weak root strength. It is difficult to manufacture rectangular thread accurately, and it is difficult to compensate or repair the gap after screw pair wear. Mainly used in force transfer mechanism. Rectangular thread calculation: tooth width = pitch – groove width groove width =0.5* pitch + (0.02~0)

4. Serrated teeth

The tooth type is a bit like a sawtooth. It is an isosceles trapezoid. The tooth side Angle of the working face is 3 degrees, and the tooth side Angle of the non-working face is 30 degrees. The root of the external thread has a large rounded Angle to reduce the stress concentration. After the internal and external thread is rotated, the large diameter has no gap for easy centering. It has the characteristics of high rectangular transmission efficiency and high strength of the tooth root of the trapezoidal thread. Drive thread for unidirectional force.

5. Ball thread

The ball screw is a circular arc groove. The ball rolling form is used to drive the screw and nut. The clearance between the screw and nut can be eliminated by replacing the ball. Therefore, the transmission efficiency is high, the precision is high, the mute effect is good. Has been widely used in a variety of automation equipment, machine tools and so on. The trapezoidal lead screw has been extensively replaced in the ordinary environment.

But the above several kinds of threads have their own advantages and disadvantages, special environment also has irreplaceable advantages.

From the production of the degree of difficulty: triangle teeth < trapezoidal teeth < rectangular teeth < serrated teeth < ball screw

But now ball screw ordinary 7 level precision is generally used in mass production of rolling process, most manufacturers have inventory, that in the delivery time of ball screw and late processing of the shaft end ball screw is the most easy to produce.

From the transmission efficiency: serrated teeth > trapezoidal teeth > rectangular teeth > triangle teeth > ball screw

From the constant bearing capacity: serrated teeth > trapezoidal teeth > hold teeth > triangle teeth > ball screw

In addition, triangle teeth are just ordinary threads used in fixing screws, most of which are standard parts. Rectangular teeth and serrated teeth are difficult to process, the precision is not easy to control and the application scenarios are very limited.