Roof Bolt Division

A comprehensive range of steel rock reinforcement tendons (roofbolts) are manufactured in Alrode (Alberton) and marketed to gold, platinum, coal and other local and export markets. The product mix consists of a well differentiated range, and coupled with low cost manufacturing technology, this division has established a durable competitive market position over time.

Expansion Shells

Expansion Shells

The unique 3-leaf expansion unit has exclusive features that ensure positive anchorage under the most arduous conditions. The expansion unit, which is available as a 'bail type' unit, is a 3-leafed mechanical anchor which conforms to the hole diameter. This feature ensures a more even load distribution between the anchor and the rock at the anchor point.

Product types:
Threaded Rock Studs

Threaded Studs - Mechanical Anchor Bolt

Mechanically anchored (also known as end anchored) rock bolts or rock studs, are extensively used in the support of underground excavations. This type of support is recommended for the short to medium term where no subsequent support of a more permanent nature is envisaged i.e. shotcrete and or wire meshing and lacing.

Product types:
Unibar™

Unibar™ - Mechanical Anchor Bolt

The cold form thread pattern on the Unibar™ gives closer tolerance between thread and nut (no 'rattle fit') and greater tensile strength. These features combined, provide improved load retention capability, compared to conventional hot-rolled fully threaded bar.

Product types:
Z-Bar

Z-Bar

Z-Bar is a hot-rolled bar formed to give superior performance when used in conjunction with the latest resin bolting technology. The bar is designed in such a way that the nominal diameter of the bar approximates the pitch diameter of the thread, thus allowing for maximum thread strength, in relation to nominal bar diameter.

Product types:
Thread bar 500

Thread bar 500

No reduction in load capabilities as threads exceed the nominal bar diameter. Robust thread design accepts harsh conditions without affecting threadability. Increased bond strength achieved owing to large surface area of ribs. Continuous thread enables retensioning in the event of ‘scaling’, as well as cutting of the bar at any point.

Product types:
Durabar

Durabar® - Yielding Roof Bolt

Durabar® is an engineered yieldable tendon capable of providing effective support in areas with swelling ground and areas prone to seismic activity. A risk assessment done by SRK Consulting indicates that financial and safety risks should decrease one hundred fold when using yieldable Durabar® instead of rebar as support under similar circumstances.

Product types:
Shepherds Crook

Shepherds Crook

Shepherds Crooks/grout rods are manufactured to client specification in a variety of arm lengths and from steels to meet the specified requirements. They are manufactured in smooth or deformed steel conforming to the requirements of SABS 920 and in accordance with our ISO 9001 quality listing.

 

Product types:
Cone Bolts

Cone Bolts - Yielding Roof Bolt

The cone bolt is a yielding tendon capable of providing effective support in areas prone to seismic events and high stress changes. Damage to tunnels normally resulting from, or associated with, rockbursts and large quasi-static rock deformations are consequently reduced.

Product types:
Pigtail Eyebolt

Pigtail Eyebolt - Suspension Bolt

Pigtail eyebolts are threaded at one end for the attachment of an expansion unit. The other end is hot worked to form a pigtail eyebolt for suspension of air, water, refrigeration and ventilation columns as well as for electrical telephone cable and chain type handrails.

Product types:
Rope Eyebolts & Wedges

Rope Eyebolts & Wedges

Rope eyebolts have a ferrule swaged to the rope at the end which is secured in the hole by the wedge. Another ferrule is swaged to the other end, onto which an eye is welded.

Product types:
DURASTUD™ - MECHANICAL ANCHOR BOLT

Durastud™ - Mechanical Anchor Bolt

The expansion shell on this mechanically anchored friction bolt provides active end anchorage and the expandable ‘C’-section ensures the integrity of the prestressing should scaling take place around the collar of the hole.

Product types:
Gemini Bar®

Gemini Bar®

Gemini Bar® is the elegant solution for full column grouted mechanical anchor bolts. It is a cold rolled, fully threaded bar made up of twin halves, resulting in a breather hole down its middle. An expansion shell is fitted to one end and at the other end a free running nut, seat, load indicator and bearing plate are attached. A short grouting tube with a gasket completes the assembly.

Product types:
Duragrout

Duragrout

Duragrout is a medium to fast setting, thixotropic, non shrinking grout, which flows easily and stiffens in-situ. It is designed to achieve good initial strength, gaining further in strength after the initial set has been achieved.

Product types:
Friction Rock Anchors

Friction Rock Anchors (Split Sets)

Friction rock anchors are simply a long length of open seam, high strength steel tube. One end is equipped with a welded steel ring which retains a bearing plate. The opposite end is tapered to facilitate easy insertion into the drilled hole in the rock. The friction rock anchor is driven into a drilled hole slightly longer and slightly smaller in diameter than the unit.

Product types:
Rotary Auger Drill

Rotary Auger Drill

Rotary auger type drill steels are used to drill shot holes and rock bolt holes in the softer measures typically found on coal mines. They are used in conjunction with hand-held electric drilling machines. Removal of the drill chips is effected by the auger action of the drill steel and water is not required to flush the drill hole.

Product types:

Roof Bolt Accessories


Accessories for rock bolts include various types of bearing plates (washers), nuts (threaded according to the stud to which they are fitted) and spherical seats.

Product types:
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