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hot crushing strength

Compressive strength of brick at high temperature.

hot-dip coating

The process of dipping metal components in molten tin or zinc to protect
them against corrosion. See also:galvanizing

hot-dip galvanizing

Immersion of iron or steel articles in a bath of melted spelter, to
produce a zinc coating. Pryor, 3

hot-drawn

Elongation of metal wire, tube, or rod by drawing it while heated through
a constricting orifice. Opposite of cold-drawn. Pryor, 3

hot forming

Working operations such as bending, drawing, forging, piercing, pressing,
and heading performed above the recrystallization temperature of the
metal. ASM, 1

hot laboratory

A laboratory designed for the safe handling of radioactive materials.
Usually contains one or more hot cells. Lyman

hot-laid type

A bituminous pavement that is mixed and laid at relatively high
temperatures, generally above 250 degrees F (121 degrees C). The highest
type pavement that can be laid, it has greater durability and lower
maintenance than any other type. Pit and Quarry

hot material

Any material that, at the time of charging, is at a temperature of 70
degrees C or higher.

hot-metal ladle

A ladle for the transfer of molten iron from a blast furnace to a mixer
furnace and from there to a steel furnace; alternatively, the ladle may
transfer molten pig iron direct from blast furnace to steel furnace. Such
ladles are generally lined with fire clay refractories, but for severe
conditions high-alumina and basic refractories have been tried with some
success. Dodd

hot-metal mixer

A large holding furnace for molten pig iron. The capacity of these
furnaces, which are of the tilting type, is up to 1,400 st (1,270 t). Hot
metal mixers may be active (that is, the pig iron is partially refined
while in the furnace) or inactive (that is, the pig iron is merely kept
molten until it is required for transfer to a steelmaking furnace). In
either case, the bottom and walls of the furnace are made of magnesite
refractories and the roof of silica refractories. Dodd

hot miller

A tool operated by compressed air, fitted with cutting wheels that mill
the hot cutting edges or rock drill bits to the required angle.
See also:detachable bit

hot-quenching

Quenching in a medium at an elevated temperature. ASM, 1

hot rolling

The passing of hot steel bars through pairs of steel rolls to form
rolled-steel sections. The final dimension of the product is approached in
stages by adjusting the height of the rolls. Nelson

hot shortness

Embrittlement of steel or wrought iron when hot, usually due to excessive
sulfur content. Pryor, 3

hot spot

a. A small portion of a furnace shell that is warmer than the rest. It
indicates a thin lining. Fay
b. The zone of highest temperature within a glass-melting furnace.
ASTM

Hot Springs diamonds

Quartz crystals found near Hot Springs, AR.

hot top

A refractory-lined steel or iron casting inserted into the tip of a mold
and supported at various heights to feed an ingot as it solidifies.
ASM, 1

hot-wire anemometer

Instrument particularly suited to the measurement of very low air
velocities and the fluctuating velocities that occur in turbulent flow.
Basically, it consists of a wire or wires, usually platinum, supported in
a frame and heated electrically. When exposed to an air current, the
heated wire cools, and as a result, its electrical resistance alters. The
heated wire forms one arm of a Wheatstone-bridge-type circuit, and
measurements of resistance change may be correlated with the velocity of
airflow that caused that change. Roberts, 1

hot working

Deforming metal plastically at such a temperature and rate that strain
hardening does not occur. The low limit of temperature is the
recrystallization temperature. ASM, 1

hourglass structure

A type of zoning, esp. common in clinopyroxenes and chloritoids, in which
a core, distinguished from the outer part by a difference of color or
optical properties, has a cross section resembling that of an hourglass.
AGI

house

a. Corn. A large mass of rich tin ore. Also called a carbona.
Arkell
b. Eng. See:gunnie; turnhouse.