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Thedford crown bit
| Diamond Glossary (алмазы и бриллианты - глоссарий терминологии) |
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Simulated insert bit, английский
A core bit in the face of which are deeply cut, closely spaced waterways to produce the superficial appearance of an insert-type bit. also called thedford crown bit.
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Simulated insert bit, английский
A core bit in the face of which are deeply cut, closely spaced waterways to produce the superficial appearance of an insert-type bit. also called thedford crown bit.
Shot drill, английский
A core drill generally employed in rotary-drilling boreholes of less than 3 inches to more than 6 feet in diameter in hard rock or concrete, using chilled-steel shot as a cutting medium. the bit is an annular-shaped, flat-face, steel cylinder with one or more diagonal slots cut in the bottom edge. as the bit and attached core barrel are rotated, small quantities of chilled-steel shot are fed, at intervals, into the drill stem with water. the shot works its way under the flat face of the bit and wears away the rock as the bit rotates. at intervals the core is removed from the borehole in somewhat the same manner as in diamond core-drilling operations. also called adamantine drill, calyx drill.
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