Tap Hole: Opening in the furnace breast through which the molten metal is tapped into the spout.
Temper: 1. The moisture content of a sand at which any certain physical test value is obtained, i.e., temper with respect to green compressive
strength, permeability, retained compressive strength, etc., 2) to mix material with enough liquid to develop desired molding properties,
3) reheating, hardened, normalized or mechanically worked steel to a temperature below the critical range to soften it and improve impact strength.
Temper Brittleness: Brittleness that results when certain steels are held within or are cooled slowly through a certain range of temperature below the transformation range. The brittleness is revealed by notched-bar impact tests at room temperature or lower temperatures.
Temper Stressing: Quenching in water from the tempering temperature to improve fatigue strength.
Temper Water: Water added to sand to give proper molding consistency.
Temperature: Degree of warmth or coldness in relation to an arbitrary zero measured on one or more of accepted scales, as centigrade, Fahrenheit, etc.
Temperature, Effective: An arbitrary index combining into a single value the effect of temperature, humidity and air movement on the sensation of
warmth or cold felt by the human body.
Temperature, Holding: 1. Temperature above the critical phase transformation range at which castings are held as a part of the heat treatment cycle,
2. The temperature maintained when metal is held in a furnace, usually prior to pouring.
Temperature, Pouring: The temperature of the metal as it is poured into the mold.
Tensile Strength: The maximum load in tension which a material will withstand prior to fracture. In the case of ductile materials, fracture is preceded by elongation and consequent reduction in cross-sectional area. The maximum stress is calculated just prior to the necking down of the test piece.
It is calculated from the maximum load applied during the test divided by the original cross-sectional area.
Ternary Alloy: An alloy that contains three principal elements.
Test Lug: An earlike projection cast as part of the casting and later removed for testing purposes.
Thermal Conductivity: The property of matter by which heat energy is transmitted through particles in contact. For engineering purposes, the amount of heat conducted through refractories is usually given in Btu per hour for one square foot of area, for a temperature difference of one degree
Fahrenheit, and for a thickness of one inch, Btu/hr-ft2-F/in.
Thermal Contraction: The decrease in a linear dimension and volume of a material accompanying a change of temperature.
Thermal Expansion: The increase in a linear dimension and volume of a material accompanying a change of temperature.
Thermal Fatigue: Failure resulting from rapid cycles of alternate heating and cooling.
Thermal Shock: Stress developed by rapid and uneven heating of a material.
Thermal Spalling: Breaking up of refractory from stresses which arise during repeated heating and cooling.
Thermal Stability: Resistance of a material to drastic changes in temperature.
Thermocouple: A device for measuring temperatures by the use of two dissimilar metals in contact; the junction of these metals gives rise to a measurable electrical potential which varies with the temperature of the junction. Thermocouples are used to operate temperature indicators or heat controls.
Thermography: 1. The technique of obtaining a photographic record of heat distribution in a solid or fluid, 2. a raised printing process employing heat.
Tie Piece: Bar or rod-shaped piece built into a pattern and made a part of the casting to prevent distortion caused by uneven contraction between separated members.
Tight Flask: 1. A flask with a rigid framework as opposed to a snap flask. 2. A type of flask which remains on mold during pouring. Lugs are normally provided for clamping cope and drag together for pouring.
Tile: Rectangular refractory shape larger than brick and usually comparatively thin.
Titanium: A white metallic element, melting point 1660 C (3020 F), having a high strength-to-weight ratio; useful in aircraft parts.
Tolerance: See Allowance.
Tooling Points: Reference points on drawings of a pattern or a casting to guide patternmaker or machinist in subsequent finishing operations and in dimension checks.
Tool Steel: Any high-carbon or alloy steel used to make a cutting too[ for machining metals and for metalcasting dies.
Torsion: Strain created in a material by a twisting action.
Tower Oven: Vertical, continuous core oven with suspended shelves attached to sprocket-driven chains.
Trace: Extremely small quantity of an element, usually too small to determine quantitatively.
Tramp Element (Trace): Contaminant in the components of a furnace charge, or in the molten metal or castings, whose presence is felt to be
either unimportant or undesirable to the quality of the casting.
Transfer Ladle: A ladle that may be supported on a monorail or carried in a shank and used to transfer metal from the melting furnace to the holding
furnace or from furnace to pouring ladles.
Transformation (Temperature) Range: The critical temperature at which a change in phase occurs. To distinguish between the critical points in heating and cooling those in heating are referred to as the Ac points (c for Chauffage or heating) and Ar for cooling (r for Refroidissement).
Tungsten: Steel-gray, metallic element, mp 3380 C (6116 F), used for electric lamp filament, x-ray tube target and as alloy element in high-speed steels.
Turntable: The base on which a centrifugal casting mold rests.