HRB® Bolt

Hollow Steel Bolt for Resin or Grout Installations

The HRB® bolt is a hollow steel bolt used in resin or grout installations, typically in hard rock mines where larger diameter support holes are drilled. The 27mm HRB® bolt is typically used with 34mm, 36mm and 38mm diameter holes. This ensures that the correct ratio between hole diameter and bar diameter (annulus) is achieved. The HRB® bolt has a tensile strength of 135 kN and is manufactured in most standard lengths. In narrow stope heights, the bolt can be supplied with a coupler to facilitate the installation process. The HRB® bolt can be galvanised or DiSTeK™ coated if required.

Advantages

• The most cost effective system for larger hole resin installations
• Ensures correct annulus for large diameter holes when used with resin grout
• The patented bar end ensures optimal resin mixing
• The bar profile ensures an optimised bond between bar and grout
• Cement grouting can be done through the centre of the bolt to ensure full column grouting
• Can be fitted with a mechanical anchored shell
• Easier to handle underground due to its lower mass
• Can be fitted with the patented Load Indicator

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Katbar®

Mining-Specific Rebar for Rock Reinforcement

Mining-specific rebar has been developed to improve on the performance of conventional rebar in mine rock reinforcement applications. Katbar® may be used with mechanical anchoring and/or grouting, especially where re-tightening of the anchor is required.

Katbar® is hot rolled during the manufacturing process with a surface geometry that provides a continuous coarse-pitch twin-start thread. This alleviates the need to separately roll a thread onto the bar, and the bar may be simply cut to length.

During use, fully threaded bar overcomes the limitations of a finite thread and is applied where re-tensioning of the installation is required (such as rock scaling) or where insertion depth is inconsistent.

Katbar® is compatible with cementitious grout, chemical resin, mechanical anchoring or combinations of these. Katbar® is supplied assembled, with variations in bar diameter and length, washer type and size, nut and seat, as well as optional load indicators, nibs, and mechanical expansion shells.

Advantages

• Continuous hot rolled twin-start thread
• Permits re-tensioning of installations
• Allows variable insertion depth
• Thread profile provides good contact surface area and geometry for grouting media (resin or cement)
• Purpose-designed surface geometry to optimise performance in underground applications

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Mechanical Anchored Rock Bolts

Immediate Point-Anchored Support

Rock bolts (or studs) are mechanically point anchored within the rock using 3-leaf bail-type expansion shells attached to the inserted end of the bolt. Expansion shells are supplied screwed onto the end of the rock tendon and are inserted into the hole. When tension is applied to the tendon, the tapered plug within the shell forces the leaves to move outwards, wedging them securely against the borehole walls. This makes the mechanical bolt functional immediately upon installation.

In many applications, the installation is post-grouted for additional stability. The complete rock bolt assembly typically includes the threaded bar, bearing plate (washer), nut, seat, and expansion shell. Numerous combinations are available to suit specific strata control requirements.

These include variations in bar type, bar diameter, thread type, expansion shell size, washer profile, and washer dimensions. All round and deformed (ribbed) bar used for mechanical anchors is manufactured from high tensile (minimum 480 MPa) steel hot rolled in accordance with SABS 920. Step Bar® and Katbar® are specifically designed for mining applications (refer to their respective Product Information Sheets for more detail).

Advantages

• Provides immediate active support upon installation
• Wide range of combinations available for tailored solutions
• Can be post-grouted for enhanced long-term stability
• Wedge and leaf arrangement ensures parallel contact with hole walls
• Tolerates up to 4 mm range in hole diameter (depending on shell type)

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Resin Anchored Rock Bolts

Chemical Anchoring for Reliable Ground Support

Rock bolt assemblies for resin anchoring (chemical anchoring) are supplied as complete, ready-to-install units. Each assembly typically includes the stud, nut, bearing plate washer, and a selection of accessories or modifications configured to suit specific installation and rock support requirements.

Resin anchoring provides an efficient, chemical-bonded reinforcement solution, offering strong and consistent load transfer between the bolt and surrounding strata. The system is especially effective in challenging ground conditions where mechanical anchoring alone may not suffice.

Advantages

• Provides stiff and secure ground support
• Cost-effective solution for a wide range of mining applications
• Improved anchorage performance in friable or weak ground conditions
• Unique ribbed design enhances resin mixing and bonding efficiency

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Split Set

Immediate Frictional Rock Support

Split Sets provide rapid, reliable rock reinforcement and can be installed using either handheld or mechanised equipment such as Jumbos and Roof Bolters. They deliver immediate support at the face and can be galvanised or coated with Distek™ for enhanced corrosion resistance.

Manufactured from high tensile steel and roll-formed into open slotted tubes, Split Sets generate radial force when driven into a hole slightly smaller than the tube diameter. This frictional resistance ensures effective load transfer. A steel ring at the collar end secures a bearing plate for added stability.

Advantages

• Provides immediate and full-length support
• Fast and easy to install with simple equipment
• Effective at any angle of installation
• Cost-effective with batch identification for traceability
• Allows easy visual inspection and monitoring
• Ideal for retaining welded mesh and areal support systems
• Performance improves with rock movement due to frictional support

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Welded Mesh

Surface Confinement for Safer Excavations

Welded Mesh provides reliable confinement to loose rock between installed rock bolts in underground mining excavations. Available in a variety of sheet sizes, apertures, wire diameters, and finishes (black or galvanised), it is tailored to meet the needs of both metal and coal mining operations.

When properly installed, Welded Mesh creates a rigid support structure that prevents sagging and reduces the risks associated with Fall of Ground (FOG) accidents. Its high tensile strength and durability make it a dependable choice for long-term strata control.

Advantages

• High corrosion resistance when galvanised
• Excellent tensile strength for demanding conditions
• Lightweight and easy to install
• Rigid structure prevents sagging
• Durable and long-lasting when correctly applied
• Reduces risk of Fall of Ground (FOG) incidents
• Contributes to a safer working environment

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Osro Straps

Continuous Areal Coverage for Fractured Rock

Osro Straps are designed to support fractured ground by creating a continuous mesh connection between anchor points. They are secured with two or more rock anchors and can be bent to conform closely to rock surfaces, ensuring effective support across irregular ground.

Compatible with any rock bolt spacing, Osro Straps provide versatile coverage for fractured strata. By overlapping strap edges, large support areas can be established to meet the requirements of more challenging excavation environments.

Advantages

• Provides large areal coverage for fractured rock
• Available in multiple lengths and widths
• Compatible with all bolt spacing patterns
• Edges can be overlapped to extend support coverage

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W-Straps

Steel Plate Containment for Fragmented Ground

W-Straps deliver continuous steel plate support between rock bolts, helping to stabilise fractured and fragmented ground conditions. Secured with two or more bolts, W-Straps conform to major surface irregularities for dependable ground containment.

Manufactured from hot rolled commercial-grade mild steel, W-Straps are available in a variety of lengths and feature evenly spaced holes to simplify installation. Their robust design ensures reliable strata control across demanding underground environments.

Advantages

• Provides large containment area for fragmented rock
• Available in a range of lengths for site flexibility
• Manufactured from durable mild steel
• Evenly spaced bolt holes for efficient installation

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Combo / Combi Plates

Economical Areal Coverage for Fractured Ground

Combo Plates provide an economical way to achieve greater areal coverage, improving the effectiveness of rock support in fractured ground conditions. Their lightweight, ergonomic design makes them easy to handle and install while ensuring close conformity to the rock surface.

For enhanced durability, Combo Plates can be treated with DiSTeK™ to improve corrosion resistance, making them suitable for demanding underground environments.

Advantages

• Economical support solution
• Lightweight and ergonomic for easier handling
• Conforms easily to rock surfaces for improved contact
• Increases areal coverage for fractured ground
• Optional DiSTeK™ coating for corrosion resistance

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Bearing Plates (Washers)

Load Distribution for Rock Anchor Installations

Bearing plates are essential components in rock anchor installations, providing areal support and distributing loads evenly across the rock surface. They are available in multiple profiles, sizes, and thicknesses, each tailored to specific strata control requirements.

Profiles include:

• Flat: Simple design with a bolt hole, suitable for flat surfaces.
• Domed: Allows articulation for angled holes or uneven rock surfaces, ensuring flush contact and improved pull-through strength.
• Ribbed: Provides added stiffness and strength, ideal for flat surfaces with bolts installed at right angles.
• Dog Ear: Includes a corner hole for suspending lightweight items such as cables or ventilation brattices.

Advantages

• Ensures proper load distribution on the rock surface
• Multiple profiles available for varying ground conditions
• Domed plates enable self-alignment on uneven rock
• Ribbed plates provide enhanced stiffness and support
• Optional dog ear design allows suspension of accessories

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Diamond Mesh

Flexible, Economical Ground and Surface Support

Diamond Mesh is a cost-effective solution widely used for roof support, sidewall support, and general applications such as fencing. Supplied in rolls, Diamond Mesh is easy to transport, handle, and install, making it an efficient choice for underground operations.

Its flexibility allows it to conform easily to uneven surfaces while maintaining strength and reliability. Multiple rolls can be seamlessly joined to achieve the required coverage.

Advantages

• Supplied in rolls for easier handling and transport
• Allows seamless joining of multiple rolls
• Flexible enough to conform to undulating surfaces
• Durable design prevents premature weld failures

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Pigtail Eye Bolts

Suspension Solution for Underground Services

Pigtail Eye Bolts are designed for suspending underground services such as pipes, conduits, and utilities. They are secured by means of a mechanical expansion shell, providing a reliable and reusable suspension solution.

Advantages

• Reusable suspension bolts
• Available in different lengths and diameters
• Quick and simple manual installation

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Flexible Eyebolts & Wedges

Versatile Suspension and Rigging

Flexible Eyebolts are mainly used for rigging underground snatch blocks and pulleys. They are secured using wedges and are available with either round eyes or link lock eyes (“Cobra”). Their reusability makes them a practical and cost-effective option for underground applications.

Advantages

• Reusable suspension bolts
• Available in different lengths
• Quick manual installation
• Suitable for suspending a variety of equipment
• Only wedges need replacement, reducing costs

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Expansion Shells

Mechanical Anchoring for Rock Bolts

Expansion Shells provide secure point anchoring for rock bolts and studs within drilled holes. Supplied pre-assembled or loose, the shell expands when tension is applied, forcing the leaves outward to wedge firmly against the borehole wall. This ensures immediate stability in both hard and soft rock conditions.

Advantages

• Effective in both hard and soft rock applications
• Available loose or pre-assembled onto rock bolts/studs
• Wedge and leaf design ensures parallel borehole contact
• Tapered plug threaded diameters available from 16 mm to 24 mm
• Options available in metric, imperial, or DIN 405 standards

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Torque / Load Indicators

Reliable Load Verification for Installations

Torque / Load Indicators are positioned between the nut and bearing plate washer, providing a clear indication of whether minimum load has been achieved on a rock support installation. Constructed from domed and profiled steel plates, they collapse during tensioning, spreading and flattening under load. Lack of collapse highlights a sub-standard installation.

Advantages

• Available in different collapse load ratings
• Provides accurate indication of initial load
• Quick identification of sub-standard installations

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Scraper Rope

Efficient Rock Removal from Stopes

Scraper Ropes are widely used in gold, platinum, and diamond mines to remove broken rock from the stope face to a central collecting point. They are supplied rolled onto wooden drums or in custom coil lengths as per customer requirements, with an internal coil diameter of 800 mm.

Advantages

• Purpose-designed for rock removal in mining operations
• Available on wooden drums or in custom coil lengths
• Customisable to specific mine requirements

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Spinning Adaptors

Efficient Installation of Resin Anchored Bolts

Spinning Adaptors are used to install (spin) resin anchored bolts. They are available in various sizes to suit different installation requirements.

Advantages

• Purpose-designed for resin bolt installation
• Available in multiple sizes
• Durable and reliable for underground operations

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Driver Dolly

Facilitates Installation of Friction Anchors

Driver Dolly’s are used in conjunction with a Jack Hammer for the installation of Friction Anchors. They are available in a range of sizes to suit customer requirements.

Advantages

• Designed for efficient anchor installation
• Available in multiple sizes
• Simple and effective to use underground

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Impact Socket Assemblies

Installation and Pre-Tensioning of Anchored Bolts

Impact Socket Assemblies are used to install and pre-tension left-hand threaded mechanically anchored bolts. They are manufactured in different sizes to meet site-specific needs.

Advantages

• Purpose-built for left-hand threaded bolts
• Accurate pre-tensioning capability
• Available in various sizes

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Space Tell Tales

Dial-Type Rock Movement Indicator

The Spaceman rock movement indicator is a dial-type displacement gauge used as a tell-tale to indicate progressive strata separation. It consists of a faceplate dial with an indicator needle and an extension rod anchored in competent ground. Any rock movement causes measurable displacement, which is displayed through needle rotation.

Advantages

• Provides early warning of strata separation
• Detects even slight rock movement
• Permanent installation with robust design
• Calibrated faceplate for accuracy
• Easy to install and operate

Dimensional Specifications

• Displacement (full scale): approx. 30 mm
• Graduation: 2 mm zones
• Deflection ratio: ~9°/mm (30 mm over 270°)
• Insertion depth: ≥200 mm beyond bolt depth
• Extension rod diameter: 7 mm
• Required hole diameter: max. 22 mm

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Rock Tale

Electronic Roof Instability Warning Device

The RockTale is a unique electronic monitoring device that provides early warning of roof instability in underground mines. It uses two LED lights (blue and red) to signal roof parting as small as 3 mm. RockTales are supplied in customizable lengths and are colour-coded for easy identification.

Advantages

• Provides early warning of roof instability
• 24/7 continuous monitoring
• Customizable length options
• Highly sensitive and reliable
• Dust and water resistant
• Eliminates human error

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