Advantages and Characteristics as below: 1. No casings required, because anchor bars can be drilled into loose soils without needing casings to support the boreholes. 2. Fast drilling and installation, because drilling, installation and grouting are in a single operation. 3. Both rope threads and trapezoid threads are robust and ideal for rotary-percussive drilling and ensuring a high level of bond with the borehole gout. 4. The hollow core not only serves for flushing during drilling, but also for grouting after drilling. 5. Continuous threads ensure the bars can be cut and coupled at any point, or extended. 6. Different anchor bits are available for different ground conditions. R thread anchor bar or called rock bolt, soil nail, which is a kind of threaded hollow bar, bar surface with an rope thread according to ISO 10208 & 1720. It was firstly invented by MAI on 1960S to solve the low construction speed on complicated underground works, nowadays; it is very popular all around the world. 
