Bolt tensioners are devices designed to apply a specific tension to a bolt. The device may be either removed once the actual nut is threaded into place, or left in place, in the case of a hydraulic nut.
The metric system does away with all of the different units of volume used in the English system, and instead, uses only one unit to measure volume. That unit is called the liter. Materials Needed: Meter stick or metric ruler; stiff cardboard such as poster board; scissors or hobby knife; tape.
A hydrometer or areometer is an instrument that measures the specific gravity (relative density) of liquidsâthe ratio of the density of the liquid to the density of water. A hydrometer is usually made of glass, and consists of a cylindrical stem and a bulb weighted with mercury or lead shot to make it float upright. The liquid to test is poured into a tall container, often a graduated cylinder, and the hydrometer is gently lowered into the liquid until it floats freely. The point at which the surface of the liquid touches the stem of the hydrometer correlates to specific gravity.