Product Description

Product Introduction

Hollow anchor bar means a rod that transfers the structures or geotechnical load to a stable rock formations, anchor bolt consists of bar, drill bit, coupling, plate, grouting stopper and nut. Widely used as an efficient anchoring means, in tunnel pre-support, slope, coast, mine, water conservancy projects, building foundation, roadbed reinforcement and geological diseases treatment such as landslip, crack, sink age. It’s irreplaceable in narrow construction environment. Hollow anchor bar is made of seamless tube with high strength.

Features of Hollow Grouting Anchor Bar:
• Fits standard Boomer, CZPT and Mustang rigs.
• Particularly suitable for difficult ground conditions.
• A high rate of installation since drilling, placing and grouting can be performed in 1 single operation.
• Self drilling system eliminates the requirement for a cased borehole.
• Installation with simultaneous drilling and grouting possible.
• Easy installation in all directions, also upwards.
• Suitable for working in limited space, height and in areas of difficult access.
• Simple post grouting system.
• Hot-dipped galvanizing for corrosion protection

Advantages and Characteristics :
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 CZPT with the borehole gout.
4.The hollow core not only serves for flushing during drilling, but also for grouting after
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.
7.Duplex anti-crossion prosess ,hot-dip galvanized and epoxy coating system.

Product Specification

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 15718 & 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: ISO15718, ISO1720 etc.

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: ISO15718, ISO1720 etc.

R-Thread Hollow anchor Bar
Size O.D(mm) I.D(mm) Ultimate Load(KN) Yield Load(KN) Weight(kg/meter)
R25N-14 25.0 14.0 200 150 2.3
R32L-22 32.0 22.0 220 180 2.8
R32N-21 32.0 21.0 280 230 2.9
R32N-18.5 32.0 18.5 280 230 3.4
R32S-17.5 32.0 17.5 360 280 3.5
R32S-15 32.0 15 360 280 4.1
R38N-21 38.0 21.0 500 400 4.8
R38N-19 38.0 19.0 500 400 5.5
R51L-38 51.0 38.0 550 450 6.0
R51L-36 51.0 36.0 550 450 7.6
R51N-36 51.0 36.0 800 630 7.6
R51N-33 51.0 33.0 800 630 8.4
T76N-49 76.0 49.0 1600 1200 16.5
T76S-45 76.0 45.0 1900 1500 19
T-Thread Hollow anchor Bar
T30-11 30.0 11.0 320 260 3.3
T30-14 30.0 14.0 275 220 2.9
T40-16 40.0 16.0 660 525 7.1
T40-20 40.0 20.0 540 425 5.6
T52-26 52.0 26.0 930 730 10
T73-56 73.0 56.0 1035 830 10.8
T73-53 73.0 53.0 1160 970 14
T73-45 73.0 45.0 1600 1270 17.5
T73-35 73.0 35.0 1865 1430 21.2
T103-51 103.0 51.0 3660 2670 44
Steel grade Acc. to EN10083-1 / EN15710-1
Thread direction Left hand / Right hand


Product and Factory Display

Product Test

Application Scope

During the constructions of underground works, it is very common to encounter soft rock, fractured zone and large deformation due to high ground stress. In the case of serious collapsing, extra-long anchor is needed instead of ordinary one.
Technology Process
The Self Drilling Anchor system is comprised of a hollow threaded anchor bar with a sacrificial drill bit that performs drilling,anchoring and grouting in a single operation. Self drilling anchor system is mainly used in slope stabilization, tunneling pre-support, foundations with micro piles etc projects.

1. Connect the alloy drill and anchor rod 1 end, on the other end, connect the drill sleeve and shank adapter, then connect the drilling rig or hand-held drill. Then start drilling, fill the cooling water while drilling.( If you want to lengthen the anchor rod, can connect the coupling, and then drilling)
2. Take down the drill, put the stop-grouting plug into the rod, and insert it to the hole, then ready to grout. Special circumstances like surrounding rock grouting tension is over or surrounding rock is too broken, can use anchor agent to seal the hole.
3. Connect quick grouting coupling and anchor rod end, connect other end of grouting machine.
4. Start grouting, when grouting full and reach design value then power off. Grouting pressure according to the design parameters and grouting machine performance determine, Cement/sand reference values is 1:0 ~ 1:1, water/cement reference value is 0.45:1 ~ 0.5:1.
5. Install anchor plate and nuts, and tighten nuts.

Packaging and Shipping

The packaging is packaged in tarpaulins and wooden boxes to ensure that it will not rust and corrode in the process of encountering water.


Q1:Can you send samples?
A:Of course, we can provide customers with free samples and express shipping service to all over of the world.
Q2:What product information do I need to provide?
A:Please kindly provide the grade, width, thickness, surface treatment requirement should you have and quantities you need to purchase.
Q3:It’s my first time to import steel products, can you help me with it?
A:Sure,we have agent to arrange the shipment, we will do it together with you.
Q4:What ports of shipment are there?
A:Under normal circumstances, we ship from ZheJiang , ZheJiang , HangZhou, HangZhou ports, you can specify other ports according to your needs.
Q5:What about product prices information?
A:Prices various according to periodic price changes of raw materials.
Q6:What is your terms of payment ?
A:Payment=1000USD, 30% T/T in advance ,balance before shipment or based on BL copy or LC at sight.
Q7:Do you provide custom made Products service?
A: Yes,if you have your own design , we can produce according to your specification and drawing.
Q8:What are the certifications for your products?
A:We have ISO 9001, MTC, third parties’ inspections are all available such SGS, BV ect.
Q9:How long does your delivery time take?
A:In general, our delivery time is within 7-15 days, and may be longer if the quantity is extremely large or special circumstances occur.
Q10: How many countries you already exported to?
A:We have exported to America, Canada, Brazil, Chile, Colombia, Russia, Ukraine, Thailand, Myanmar, Vietnam, India, Kenya, Ghana,somalia and other African countries.Our export experience is rich, we familiar with different market demands, can help customers avoid a lot of trouble.
Q11:Can I go to your factory to visit?
A:Of course, we welcome customers from all over the world to visit our factory.
Q12:Does the product have quality inspection before loading?
A:Of course, all our products are strictly tested for quality before packaging, and unqualified products will be destroyed and customers can appoint third parties to inspect the products before loading too.
Q13:How to pack the products?
A: Standard export sea-worthy packaging, the inner layer has a waterproof paper outer layer with iron packaging and is fixed with a fumigation wooden pallet. It can effectively protect products from corrosion and various climate changes during CZPT transportation.
Q14:What is your working time?
A:In general, our online service time is ZheJiang time: 8:00-22:00, after 22:00, we will reply to your inquiry in the coming working day.

After-sales Service: Support
Warranty: Support
Type: Seamless
Technique: Hot Rolled
Material: Carbon Steel
Surface Treatment: Black


Customized Request


What Is a Coupling?

A coupling is a device that connects two shafts together. It transmits power from one to the other and is used to join rotating equipment. It can also allow for some degree of misalignment and end movement. It is used in mechanical engineering and manufacturing. To learn more about couplings, read this article.
Mechanical connection between two objectsThe present invention relates to a method and assembly for forming a mechanical connection between two objects. The methods of this invention are suitable for connecting both solid and hollow objects. For example, the method can be used to make mechanical connections between two cylinders. This method is particularly useful for connecting two cylinders that are positioned near each other.

Absorbs vibration

A coupling insert is a part of a vehicle’s drivetrain that absorbs vibrations. These inserts are designed to prevent couplings from moving out of phase. However, the coupling inserts themselves can wear out and need to be replaced. Universal joints are an alternative if the coupling is out of phase by more than one degree. In addition, internal bearings in the coupling need to be lubricated and replaced when they begin to show signs of wear.
Another embodiment of the invention includes a flexible coupling 25 that includes rearwardly-extending lugs that extend toward the coupling member 23. These lugs interdigitate with corresponding lugs on the coupling member 23. They are spaced circumferentially. A first elastic member 28 is interposed between lugs 26 and 27, and is adapted to yield in a counterclockwise direction. As a result, it absorbs torsional vibrations.

Blocks heat transfer

Thermal coupling occurs when a solid block is thermally coupled to the air or fluid passing through it. The amount of heat transferred through a solid block depends on the heat transfer coefficients of the materials. This paper presents a numerical model to understand how heat transfers through different block materials. This work also describes the thermal resistance network for a one-dimensional block.
In some cases, thermal coupling increases the heat transfer mechanism. As illustrated in FIG. 1D, a heatpipe coupler 112 couples two heatpipes 110-1 and 110-2. This configuration allows the pipes to be coupled to the heat source and to the condenser. In addition, the heat pipe couplers may have bellows at the ends to help facilitate linear motion.
Thermal coupling is achieved by ensuring that at least one block is made of a material with a lower thermal expansion coefficient than the annulus. Ideally, the block’s mean thermal expansion coefficient is at least twenty percent lower than the annulus’s mean thermal expansion coefficient. This ensures that the thermal coupling between the two parts is as efficient as possible.
Another type of thermal coupling is achieved by using flexible elements. These are often washers or springs. These components allow the blocks to maintain physical contact with the post 55, which means that the heat transfer is more efficient even at higher temperatures. The flexibility of these elements also makes it possible to choose an element that will not impede assembly.

Protects rotating equipment

A reliable, long-lasting coupling system can reduce the risk of damage to rotating equipment. Designed to protect against torque overload and wear, Voith torque-limiting couplings provide outstanding safety and reliability. As a result, they can deliver maximum performance and minimize equipment downtime. In addition to their long-term benefits, these solutions are ideal for applications where safety and reliability are of paramount importance.
A good coupling provides many advantages, including the ability to transmit power, compensate for axial movement, and absorb shock. It is essential to choose the proper coupling for your application based on the basic conditions of your rotating equipment. For example, if you have two shafts with parallel rotation axes, you should choose a parallel coupling. Otherwise, you should use an angular coupling.
Torque-limiting couplings can also provide protection for rotating equipment by disengaging at a specific torque level. This protects the drive shaft from undergoing catastrophic failure. Torque limiters are particularly helpful for high-value equipment. By preventing catastrophic failure, you can avoid expensive repairs and minimize equipment downtime.
Coupling guards are easy to install and provide effective protection for rotating equipment. These covers are made of sheet metal bent to fit over the shaft. They are durable and easy to remove when necessary. This type of guard can prevent employees from catching their hands, tools, or loose clothing on motor coupling components.
China wholesaler R/T Thread Seamless Steel Coupling for Hollow Bar Anchor   coupling beamChina wholesaler R/T Thread Seamless Steel Coupling for Hollow Bar Anchor   coupling beam
editor by CX 2023-08-01