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 is an instrument used to measure the specific gravity (relative density) of liquids; that is, the 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. hydrometer is an instrument used to measure the specific gravity (relative density) of liquids; that is, the 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.