Understanding Thread Specifications and Uses

They convert linear force into rotational force.

They decrease the friction between surfaces.

They increase the speed of rotation.

They convert rotational force into linear force.

Making liquid tight seals

Power transmission

Precision measurement

Creating electrical circuits

Screws are always larger than bolts.

Bolts are always larger than screws.

Screws are used with nuts, bolts are not.

Bolts are used with nuts, screws are not.

The largest diameter of a thread.

The diameter where the width of the threads and grooves are the same.

The diameter measured over the roots of the thread.

The smallest diameter of a thread.

The number of threads per inch.

The distance between two adjacent threads.

The diameter of the thread.

The angle between the sides of the thread.

Universal National Fast

Universal National Fine

Unified National Fast

Unified National Fine

Class 3

Class 4

Class 1

Class 2

The thread is left-handed.

The thread is right-handed.

The thread is for light hardware.

The thread is for heavy hardware.

Minor diameter

Metric

Medium

Major diameter

As the number of threads per inch

As the diameter of the thread in millimeters

As the number of threads per centimeter

As the distance between threads in millimeters