Hollow Bar System
Stainless Hollow Bar System
Hot DIP Galvanized Hollow Bar System
TDG Hollow Bar System
Epoxy Coating Hollow Bar System
Hollow Bar

Hollow Bar

CMP Hollow Bar System is a fully threaded hollow core bar that is initially a server as a drill rod with a lost bit, and later, once grouted in, it becomes an anchor tendon that can be stressed and locked off with a nut.

CMP hollow bar system provides the optimal solutions for nailing, bolting, micro piling and as ground anchors in difficult ground and rock conditions.

T thread
R thread
Special and Mixed

T thread self drilling anchor bolt system is composed by hollow rock bolt, anchor nut, anchor plate, anchor coupler, drill bit, centralizer, and the hollow anchor bars can be cut and lengthened by coupling on request.


★ Drilling, anchors installation and grouting are in one single operation, it is easy and fast to install.

★ An economic alternative to anchors installed with cased drilling.

★ Small workspace needed.

★ Simple systems, low requirements on personnel.

★ No separate anchor installation or removal of casing and drill rods, increase productivity.

★ Easy stressing operation.

★ Flexible in length by using couplers.

★ Choice of drill bit for different ground conditions.

Bar SizeT30NT40LT40NT52NT60NT76L T76NT76MT76ST103NT103S
  Nominal outer diameter(mm)304040526076767676103103
  Nominal Inner diameter(mm)1324203038544947448057
  UItimate load(kN)320.00540.00660.00929.001,000.00 1,200.00 1,600.00 1,700.00 1,900.00 2,300.00 3,700.00 
  Yield load(kN)260.00425.00525.00730.00800.001,000.00 1,200.00 1,300.00 1,500.00 1,800.00 2,670.00 
  Elongation A5(%)≥6.00
  Nominal weight (kg/m)
  Thread  (left-hand)CMP Internal standard and based on ISO 10208 and 1720 etc.
  Steel gradeASTM A519-035140/EN 10083-141Cr4
  Delivery lengths (m)1m,2m,3m,4m.Other length can be special order


The CMP hollow rod system is a fully threaded hollow rod that was originally a drill rod with a missing drill bit. Later, once grouted, it becomes an anchor bar that can be stressed and locked with a nut. 

The CMP hollow rod system provides the best solution for nailing, anchoring, micro piling, and serving as a ground anchor in difficult ground and rock conditions. 

It mainly includes nuts, drill bits, plates, and couplers.

Drill Bits

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Standard drill bit with hardened cross cut profile, manufactured from steel.

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For general applications with loose to medium ground conditions.