A method of determining the relative hardness of metals and case-hardened
materials. The depth of penetration of a steel ball (for softer metals) or
of a conical diamond point (for harder metals) is measured.
See also:scleroscope hardness test
Trade name for an apparatus that measures the hardness of metals and
alloys, in which a diamond-pointed cone is pressed under a specific load
into the metal. The relative resistance to penetration (Rockwell hardness)
is indicated by a number (Rockwell number) on a dial. The operation is
called a Rockwell hardness test. Syn:Rockwell tester
See:Rockwell machine
See:mountain wood
See:asbestos
A noncoring bit designed to fit a reaming shell that is threaded to couple
directly to a drill rod, thus eliminating the core barrel in blasthole
drilling. Also called blasthole bit. Long
See:clearance
Name for a double-pin-thread coupling used to connect two drill rods
together. Long
See:safety clamp
a. Cleaning and descaling of piping by means of scrapers attached to
series of jointed rods. Pryor, 3
b. Eng. The operation of fixing or repairing wooden cage guides in shafts.
c. In metamorphic rocks, a linear structure in which the stronger parts,
such as vein quartz or quartz pebbles, have been shaped into parallel
rods. Whether the structure is formed parallel to the direction of
transport or parallel to the fold axes has been debated. AGI
Grease or other material used to protect or lubricate drill rods. Also
called rod grease. Syn:gunk
The rubbing of the rods or drill string on the sidewalls of the borehole.
Syn:rod friction
The distance of slump or slag in a long string of rods when released from
the drill chuck. Long
See:elevator; elevator plug.
a. The drag created in the flow of the drilling liquid by contact and
constrictional effects created by the inside surface of the drill rods and
couplings. CF:skin friction; wall friction. Long
b. See:rod drag
A massive dense buff to pink rock typically rich in grossular garnet and
calcic pyroxene, and enveloped in serpentinite. Epidote, vesuvianite, and
other calcium-rich minerals are commonly present. It is formed by
metasomatic alteration of a protolith that, in many cases, was a dike
rock, as shown by preservation of structures. The name was applied by Bell
in 1911. AGI
A method of shaft sinking by the freezing method. It is based on the
direct cooling effect of expanding highly compressed carbon dioxide in the
freezing pipes. See also:Koch freezing process
Refers to elongate crystals. CF:acicular; equant; tabular; lathlike.
a. A person who uses or carries a surveyor's leveling rod. Also called
rodsman. Standard, 2
b. See:staff man
a. A mill for rolling rod. ASM, 1
b. A mill for fine grinding, somewhat similar to a ball mill, but
employing long steel rods instead of balls to effect the grinding.
ASM, 1
One who grinds clinker, phosphate rock, or ore in a revolving cylinder
partially filled with round steel rods; also, he or she tests a product
for fineness by observing how much material is left on sieve of determined
mesh, and regulates amount of material entering the mill accordingly.
DOT