... tungsten carbide, the wear-resistance is higher than YG8S.For geological prospecting, coal mining, tipping of electric and air drill for coal bed.YA614.4-15.092Belonging the fine tungsten carbide ... .For rough turning, planning, milling and electric drill bits.YG11C14.0-14.487Belonging the coarse tungsten carbide, the strength is a little worse than YG15.For heavy rock drill bits ...