Hollow core bolts (HC Bolts) utilise the same hollow bar as SDA but are supplied without a drill bit for applications where a convetional drill string can be used to drill the support hole. Once the HC Bolt is inserted into the pre-drilled support hole, resin or grout is injected through the bolt to complete the installation. 

Threaded Hollow Anchor Bar

The threaded hollow anchor bar forms the core structural element of the whole self-drilling anchor system. It provides the necessary load-bearing capacity and is designed to resist tension forces. The thread pattern on the rod allows for easy attachment of drill bits, nuts, plates, and other components. Self-drilling anchor bolts can be categorized based on their threading patterns. Two common types includeR-Thread Self-Drilling Anchor Bolts and T-Thread Self-Drilling Anchor Bolts.

R-Thread Anchor Bolt Technial Data

R thread anchor bar or called rock rod, 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.
Thread size: R25, R32, R38, R51, T76.
Thread standard: ISO10208, ISO1720 etc.

T-Thread Anchor Bolt Technial Data

T thread anchor bar surface with a trapezoidal thread, this design of connection is much stronger and reliable when compared with rope thread, we supply full sizes from T30 to T103.
Thread size: T30, T40, T52, T73, T103, T127, T130.
Thread standard: ISO10208, ISO1720 etc.