Mechanical blog

ABSOLUTE TEMPERATURE  The temperature of a substance measured above absolute zero. ABSOLUTE ZERO TEMPERATURE  Temperature at which all molecular motion ceases, according to the kinetic theory of gases. A point which has been determined on the thermodynamic scale (by theoretical considerations) beyond which a further decrease in temperature is inconceivable. This is equal to – 459.6° on the fahrenheit scale and – 273.1° on the centigrade scale. ABSOLUTE TEMPERATURE SCALES  Used for calculating changes in refrigerant vapour pressures. ADIABATIC EXPANSION or COMPRESSION  Expansion or compression where the temperature rises during compression and falls during expansion without any loss of heat to the cylinder walls or absorption of heat from the walls.  ADIABATIC HEAT DROP  The heat energy released and theoretically capable of transformation into mechanical work during the adiabatic expansion of unit weight of steam or other ...

ACME THREAD GAUGE A gauge used for checking and testing the 29° angle and the width at the end of a thread cutting tool while grinding it. It is also used for setting the tool square with the axis of the workpiece. 29 ° 각도와 너비를 확인하고 테스트하는 데 사용되는 게이지는 나사 절삭 공구 끝을 연마하는 동안 사용됩니다. 공작물의 축 ANGLE PLATES  Some work has to be set at a particular angle to the surface of the table, and this is often effected by bolting it to an adjustable angle plate.  ARDOMETER A type of total radiation pyrometer.  BORING BAR MICROMETER On boring operations, it is often necessary to adjust the cutter setting by a few thousandths of an inch. With this, it is possible to determine exactly the depth of cut taken. CALIPER Instrument used for measuring distances between or over surfaces, or for comparing dimensions of workpiece with such standards as plug gauges, graduated rules etc.  CENTRE SQUARE  is intended for marking the centres of round or squa...

Absolute edge The large hammer used by a blacksmiths mate turn about with the smaller hammer of the black smith. Angle cutter Type of milling cutter used for single or double angles.The term angle cutters covers three types of milling cutters, the single or half angle the doubles angle and the equal or combined angle. Back stick Piece of wood used when slinning sheet metal by hand in a lathe. Bell center punch Device used for rapidly locating and marketing the centre of the flat end of a cylindrical workpiece, preparatory to heavier centre punching, centre drilling, turning in a lathe etc. Blanking and cupping tool Tool used to cut a blank and form a cup from sheet or strip metal at one stroke of the press. Blow pipe. Gas welding torch in which oxygen and acetylene are mixed and ejected from a nozzle. Boiler Tap Hand tap specially designed for tapping holes for use with boiler stays. Boring bar Bar carrying a cutter or cutters to enable holes to be bore...

ABSOLUTE HUMIDITY  Actual quantity of water vapour in the air, usually expressed as so many grains of moisture in a cubic foot of air. ABSOLUTE PRESSURE Pressure measured from the true zero or point of no pressure. ADIABATIC COMPRESSION Compression of air without receiving or giving up heat. AFTER COOLER A type of surface heat exchanger in which compressed air is cooled after compression AIR COMPRESSOR A machine which compressed air into a receiver to be used at a greater or shorter distance. AIR COOLED COMPRESSOR A compressor whose cylinder has cast integralvnumerous thin fins to form excess cooling surface exposed to a drought of cool air which forms the medium to carry off some of the heat of compression. AIR ENGINE  A very small reciprocating engine driven by compressed air.  AIR EXHAUSTER A suction fan, a vacuum pump.  AIR METER An apparatus used to measure the rate of flow of air or gas. AIR RECEIVER...

Absolute humidity The weight of the water vapour which is associated with unit quantity of air. Absorber: A device for absorbing a refrigerant, a low side element in an absorption system. Absorption refrigeration system: One in which the refrigerant as it is absorbed in another liquid, maintains the pressure difference needed for successful operation of the system. Absorptivity Ability of a material to absorb heat. Accumulator A steel shell partly filled with liquid refrigerant, the space above which is maintained by the compressor at a pressure corresponding to the required refrigerant temperature. The shell is placed in a suction line for separating liquid entrained in suction gas. Actuators Secondary control mechanisms which function in response to the requirement of the primary group in actually controlling some part of the refrigeration system. ADIABATIC COMPRESSION Compression of a vapour or gas in such circumstances that there is insufficient time for an...