Basic knowledge of bolt threading

Basic parameters of thread:

Six elements of thread: tooth type (triangle, trapezoid, rectangle, serrated and square, etc.) Nominal diameter, small diameter, number of lines, pitch and lead, rotation. (Five elements of thread: tooth type, diameter (large diameter, small diameter, medium diameter), number of lines, pitch and lead, and rotation)

Only six internal and external threads with identical thread elements can be spun together. Thread type, large diameter and pitch are the most basic elements, called the three elements of the thread. All tooth type, diameter, pitch in line with the standard for the standard thread; The tooth type meets the standard, and the diameter or pitch does not meet the standard is special thread; The tooth type does not meet the standard is non-standard thread.

 

Use of different tooth types:

Triangular thread for connection; Trapezoid, square thread for transmission, etc.

 

Main types of threaded connections:

1) Bolt connection: ordinary bolt connection, ream hole bolt connection;

2) Screw connection;

3) Stud connection;

4) Fastening screw connection;

5) Anchor bolt connection;

6) Ring screw connection, divided into A type and B type two structures, A type without the tool slot, B type with the tool slot.

 

Common thread standards: metric, imperial and American.