Introduction Sharprazor watermelon/String mills are designed to enlarge the hole,open up windows,mill through collapsed casing,polish liner polished bore,clean up perforation section,,restore casing drift and downsize debris generated during cased hole milling or drilling applications. Our String mills have a tapered top and bottom to allow upward and downward reaming.it has spiraled blades welded with crushed tungsten carbide,full 360° wrap . Sharprazor string mils use cutting-edge technology, top experienced engineers in this scope to guarantee the quality.Standard sizes from 3-1/2to 28,and customized specification is available to suit specific operational requirements.