Plumb Bob

The plumb bob or plummet is a weight that usually has a pointed tip and is suspended from a string. It can be used as a vertical reference line also known as a plumb line.

Facts you should know about a plumb bob include:

• Some plumb bobs have metric measurements on them to ensure a more accurate measurement.
• The plumb line is also known as the water level.
• Plumb bobs usually weigh between 8-20 ounces.
• They are made out of brass, polished brass, or steel.

When you use this tool a string is fixed at the point to be plumbed or measured. The weight, or bob, is then allowed to swing freely.

When the bob stops, the point of the bob will be precisely below the point at which the string is fixed above. Once it is hung and still, the top and bottom points of the plumb bob can be marked and used as guides for measurement or vertical application.