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Mining machinery.Heavy machinery and equipment used by the mining industry in the exploration and devel- opment of solid mineral ***** is used here in the broad sense to include the extraction of solid minerals occurring naturally such as coal and ***** term min- ing also includes quarrying, milling (crushing, screening, washing, flotation, etc.), and other preparations customar- ily done at the mine site or as a part of mining activity. Portable drilling rigs for use in oil and gas fields or for drilling water wells are also included for the purpose of this survey. Auger ***** that use continuous flight auger bits for removing cuttings. Bucket ***** that rotate a bucket and remove cuttings by lifting the bucket to be dumped. Cable ***** using percussion-type tools and those that clean the hole using tubular-type bailing tools. Portable drilling rigs.Drills mounted on a carrier and used on the surface (above ground). Pull-back capacity.Lifting capacity of drawworks or hoisting capacity of taphead. Pull-down ***** to apply bit pressure. Reverse ***** using a rotary drilling process where the drill cuttings and fluid return to the sur- face inside the drill stem (large diameter holes, *8 or larger). Rotary ***** using rotary drill pipe, continu- ous fluid, and a mud pump, air compressor, or combina- tion to clear the hole of filling. Screens, ***** used for dry or wet screen- ing applications such as sizing, washing, and dewatering of ores, coal, sand, and gravel.