1, depending on the direction of rotation, there are left-handed and right-handed threads. The thread screwed in clockwise is called right-handed thread, and the thread screwed in counterclockwise is called left-handed thread.

2. When the thread or screw is perpendicular to the horizontal plane, you can see that each thread is oblique. If the right side is high, the thread is right-handed. If the left side is high, the thread is left-handed

3. The thread screwed in by hand when rotating counterclockwise is called left-handed thread, and the thread screwed in when rotating clockwise is called right-handed thread.

Extended data:

Difference between left-handed thread and right-handed thread

1, the thread rotation position is different.

Left-handed thread, when the part is placed vertically along the axis, the left end of the thread is higher than the right end.

Right-handed thread, right-handed thread is higher than left-handed thread

2, the rotation direction is different

Left-handed thread, thread screwed in when rotating counterclockwise.

Right-handed thread, screwed in when rotating clockwise.

3, thread inclination is different

Left-handed thread, put the thread vertically along the axis, and you can see that the thread has a certain inclination angle. If the left side is higher than the right side, it is left-handed thread.

Right-handed thread, when the right side is higher than the left side, is right-handed thread.

References:

Baidu encyclopedia-right-handed thread

References:

Baidu encyclopedia-left-handed thread