... and enhanced within the gage super, working-level up to 12-16mm, product performance up ... Shandong Rushan 863 scientific drilling project at the level of NQ drill bit applications, the maximum ... stable, glassy, very weak ground stratum JSC150,180,200 --- for stable, mild abrasive, hard and slippery ... severely broken, strong grinding, coarse ground JSC-level - Imports Premium grade diamond, ultra-high bit ...