Drill attachment VG0250211

Soft to Medium Formations This design is most effective in formations with compressive strengths under 5,000, such as shale, clay, red bed, medium limestone and unconsolidated formations. The BT1 also features the absence of deletions on the gage side of teeth on the heel row of the number two cone. This insures maximum gage life along with tooth life in more abrasive formations. Effective operating weights are from 1,000 to 3,000 pounds per inch of bit diameter with corresponding rotary speeds of 200 to 50 RPM. Medium to Medlum-Hard Formations The teeth are shorter "A" shaped and more closely spaced teeth than those of bits designed for softer formations. Long crests in the outer row teeth have self-sharpening hard facing applied for maximum pénétration and longer bit life. This design will most economically drill medium and medium hard formations and was designed to replace the softer formation bits in strata where shale alternâtes with streaks of limestone and sandstone or where gypsum tends to bail up between the teeth. The most effective weight range varies from 1,000 to 5,000 pounds per inch of bit diameter, while rotary speeds of 150 to 50 RPM give best performance. Rotary speed should be decreased as weight is increased.