GREAT WALL DRILLING TOOLS CO.,LTD The Casing Scraper is used to clean cement, mud, embedded bullets, rust, mill scale, paraffin, perforation burrs ... . u irnportant to the operation of all tooh used in drilling the well. likewke, packers and similar tools must have a ... Pin. Thn allows the scraper to be installed in the drilling string between the bit and the bit sub. The bit ...