English thread is the thread size marked in English, according to the shape of the cylinder, cone two; According to the tooth Angle divided into 55°, 60° two. The 1/4, 1/2, 1/8 mark in the thread is the diameter of the thread dimension in inches. An inch is 8 minutes, a quarter inch is 2 minutes, and so on.
Measurement method of inch nuts:
Measuring the Angle between threads
The Angle between the threads is also called the tooth Angle. The Angle of the thread can be measured by measuring the side Angle, which is the Angle between the side of the thread and the vertical plane of the thread axis. The approximate contour of the thread teeth is sampled in the line segment on both sides of the thread.
(2) pitch measurement
Pitch is the distance between a point on the thread and the corresponding point on adjacent thread teeth. The measurement must be parallel to the thread axis.
(3) measuring the middle diameter of the thread
The middle diameter of the thread is the distance of the middle diameter line perpendicular to the axis. The middle diameter line is an imaginary line.