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Nomenclature of screw thread

Nomenclature of screw thread:

Nomenclature of screw thread: Nomenclature of screw thread represents the futures of screw, the main function of screws is to join/combine different metal/non-metals elements together. There are various types of screws for different types of joining, and the formation of threads is done by providing a helical grooves on a circular/cylindrical metal.

Important elements:
Major diameter.
Minor diameter.
Effective diameter.
Threaded angle.
Flank angle.

Major diameter
Major diameter is also called as external diameter or core diameter.It is measured by an ideal coaxial cylinder which touches the crests and root of an outside and inside or internal thread respectively.

Minor diameter
Minor diameter is also called as root or core diameter. It is the diameter of an ideal coaxial cylinder, which touches the crests on internal and root on external thread.
Pitch is measured the distance between two consecutive crests or two consecutive troughs, must be measured parallel to the axis of the thread is called pitch.

Effective diameter
Effective diameter is also called as pitch diameter. Ideal coaxial cylinder is pitch diameter, which intersects the flanks.so the width space is equal.

Crest is the principle part of thread, it is the top surface of the thread. Which is connected by two sides of thread.

Flank is the straight surface between crest and root.
Root is the bottom side of the groove formed by two adjacent side of thread is termed as root. It is the lowest point of the thread.

Thread angle 
Thread angle is also called as included angle. It is measured between two flanks of a thread in an axial plane is known as thread angle.

Flank angle:
Flank angle is usually equal to half of the thread angle.

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