An operation in which the work, usually castings or forgings, is rotated
in a barrel with metal slugs or abrasives to remove sand, scale, or fins.
It may be done dry or with an aqueous solution. Sometimes called rumbling
or rattling. ASM, 1
A revolving barrel, cask, or box in which objects or materials (such as
small metal parts, castings, plastics, leather, or clothing) undergo a
process (such as finishing, polishing, coating, softening, or drying) by
being whirled about and so brought into vigorous frictional contact. Also
called rattler; rumble; scouring barrel. Webster 3rd
A tumbling barrel for small objects. Webster 3rd
Any horizontally mounted cylindrical mill in which contents are tumbled
when rotating. Name often used in connection with cleaning of objects.
Pryor, 3
The camshaft used in stamp mills. Fay
N. of Eng. Boulders or detached masses of rock.
The swelling of a volcanic edifice due to accumulation of magma in the
reservoir. It may or may not be followed by an eruption. Syn:inflation
AGI
A treeless, level or gently undulating plain characteristic of arctic and
subarctic regions. It usually has a marshy surface, which supports a
growth of mosses, lichens, and numerous low shrubs and is underlain by a
dark, mucky soil and permafrost. AGI
A monoclinic mineral, SrB6 O9 (OH)2 .3H2 O ;
subvitreous to pearly; colorless; forms compact fine-grained secondary
nodules; also prismatic and tabular crystals; at Kramer and in the Furnace
Creek area of Death Valley, CA.
Labor paid for by the day or the hour, in contrast to piecework.
Fay
A mineral containing the radical (WO4 )2- , in which the
hexavalent tungsten ion and its four oxygens form a flattened square
rather than a tetrahedron, e.g., the wolframite series, (Fe,Mn)WO4.
Tungsten and molybdenite may substitute for each other.
A hard, brittle, white or gray metallic element. Symbol, W. Also known as
wolfram. Found combined in certain minerals such as wolframite, (Fe,Mn)WO
4 ; scheelite, CaWO4 ; huebnerite, MnWO4 ; and
ferberite, FeWO4 . Tungsten and its alloys are used extensively for
filaments for electric lamps, electron and television tubes, X-ray
targets, and numerous space missile and high-temperature applications.
See also:wolframite
Handbook of Chemistry and Physics, 3
An alloy used in drill-bit-crown matrices and in making bit and
reaming-shell inserts by powder methods in which the principal constituent
is tungsten, generally in the form of carbide. Tungsten carbide powder
usually is mixed with a powdered cobalt or other metal to bind it together
in a cohesive mass. Long
A mixture consisting of 85% to 95% tungsten carbide and 5% to 15% cobalt;
sp gr, 12 to 16; Mohs hardness, about 9.0; it is not affected by severe
high industrial temperatures. Used for machine tools and for abrasives for
machining and grinding metals, rocks, molded products, porcelain, and
glass. CCD, 2
A drilling bit tipped with tungsten carbide. A 9% cobalt carbide generally
gives the best results, and comparisons are usually referred to bits of
this standard. Tests with tungsten carbide bits indicate that efficient
drilling is possible only up to a hardness of about 55 Shore; beyond this,
wear increases rapidly until, at 62 Shore, the cost becomes prohibitive.
Several factors affect the cutting life of the bits, including the grade
of carbide used, the rake angle of the cutters, the length of cutting
edges, and support of cutters. See also:steel bit; coal-cutter pick;
Shore hardness test; sintered carbide-tipped pick. Nelson
a. A small plate or slug of tungsten carbide alloy mounted in the crown or
shank of a bit or in grooves on the outside surface of a reaming shell to
provide wear-resistant or rock-cutting surfaces or edges. The term is
sometimes incorrectly applied to diamond-set plates of tungsten carbide
alloy inset as reaming surfaces in reaming shells. Long
b. In mining, a slug composed of tungsten carbide alloy shaped and mounted
in the bit face so that the slug acts as the cutting edge of the bit.
Long
c. Hemispherical-ended cylinders of sintered carbide are inserted in place
of the usual teeth to give 10 to 15 times the total footage and 2 to 3
times the cutting rate. However, hard rocks are drilled more economically
by diamond boring. Nelson
tungsten direct-from-ore process
An electrowinning method developed by the U.S. Bureau of Mines for
producing high-quality tungsten powder directly from ore. A strong
electric current separates the metal from the ore, which has been placed
in solution, and deposits it as a pure powder on an electrode. Electrowon
tungsten compares favorably with hydrogen-reduced tungsten.
A trigonal or hexagonal mineral, WS2 ; forms dark, lead-gray,
minute, foliated or earthy scales; at the Emma Mine, Utah.
See:ferritungstite; tungstite. Also called wolfram ocher.
An orthorhombic mineral, WO2 (OH)2 ; yellow to green; in
oxidized zone of tungsten deposits. Syn:tungstic ocher; wolframine.