Shandong Tongrui Mining Technology Co.,Ltd was founded in 2007 in Tai an, Shandong, China. In 2011 we set up GSI(Ground Support Industries Co.,Ltd) for selling and promoting the products of Tongrui under the brand name of Tightlok. Our office and factory are very near to both Qingdao and Tianjin Seaport, which makes the exporting of our products effectively, economically and quickly. We are a very professional Ground Support Products Manufactory. Over the years, by working together with many famous technicians and experts including professors from ShanDong Science & Technology University (formerly known as Shandong Mining College in China), we have brought together good experience and innovative solutions in ground control and roof support products and services for the underground mining, tunnelling, building and construction industries. Our Tightlok Split Sets have already got very good reputation in China and Overseas. GSI China has standard and modern workshops with very advanced testing center. The company manufactures an extensive variety of : --Split Set Bolt --Threadbar Bolt --Cable Bolt --Grooved Bolt --Slot & Wedge Bolt --All Threadbar Bolt --W Roof Mat & Plate --Dome Plate By integrating many typical Geological knowledges, World-wide Technical Expertises and Global Innovations, we are proficient in providing integrated solutions for all of our partners' ground control and roof support projects. We are strongly committed to product reliabilities, qualities, safeties and excellent performances. Our responsibility: to ensure the safety of laneways and protect all miners! Try our GSI ground support products, we will return you with satisfaction! Allow us to partner with you in your next project, we will return you with safe