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Novel Coal-cutting Bits and Their Wear Resistances.

Authors
Cheng-L; Liebman-I; Furno-AL; Watson-RW
Source
MISSING :15 pages
Link
NIOSHTIC No.
10003009
Abstract
Based on earlier tests that showed steel to be much more likely to cause frictional ignition than tungsten carbide, the Bureau of Mines redesigned coal-cutting bits to reduce the hazard of face ignitions. Two bit designs--a mushroom-shaped bit with a conical shank and a dovetail bit with a rectangular shank--are described, as well as bit wear tests conducted in the laboratory and in an operating coal mine. In laboratory tests, for 1/8-, 1/4,- and 1/2-in-deep cuts and cutting speeds of 280, 500, and 660 ft/min, the mushroom bit had significantly longer tip wear life than the conventional bit; the dovetail bit was also superior to the conventional bit. Results of in-mine tests on the mushroom bit agreee well with laboratory results. In-mine tests of the dovetail bit are underway.
Publication Date
19830101
Document Type
IH; Report of Investigations
Fiscal Year
1983
NTIS Accession No.
NTIS Price
Identifying No.
RI 8791
NIOSH Division
PRC;
Source Name
MISSING
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