Which grades are useful in earth drilling or boring applications?
In many respects the characteristics of the grades employed for earth drilling and boring represent a compromise between the characteristics that are important for metalcutting and those that are important for metalforming applications. Grades for earth drilling and boring must possess the highest toughness levels for any given abrasion resistance level, while simultaneously possessing adequate strength levels. The best compromise is usually arrived at by using grades that are based on coarse grain sizes (3 to 8 m) and relatively low Co levels (6 to 16 wt. %).
