Complete resin-grouted roof bolt assembly sets and individual components: all manufactured in-house at our MIDC, Chandrapur facility and tested before dispatch.
Every product manufactured in-house. No prices listed: submit an RFQ with your specification for a formal quotation.
Full resin-grouted assembly: threaded bolt, W-strap, domed plate, conical seat cum nut, domed washer, hexagonal nut, and shear pin. Packed and documented per DGMS Cir. 3/2010.
Corrugated W-profile steel straps formed in-house for consistent dimensional tolerances. Distributes bolt load across roof panels in roadway and gallery applications.
Combined conical seat and nut for the spin-to-stall system. Conical angle ensures accurate seating; thread engagement verified against DGMS Category C parameters.
Dome-shaped steel washers that seat between the conical nut and domed plate, providing a load-bearing transition and angular compensation during spin-to-stall installation.
Heavy-duty hexagonal nuts manufactured to DGMS thread tolerances. Thread gauged 100% in-house using Go/No Go gauges before inclusion in assembly sets.
Hot-dip galvanized hexagonal nuts for corrosive underground environments. Provides extended service life in high-humidity and saline mine conditions.
Hot-dip galvanized version of the domed washer for corrosion-resistant assemblies. Used wherever ground conditions or regulatory requirements specify galvanized hardware.
Dome-pressed steel plates with spherical seating surface that self-aligns to any bolt installation angle. Dimensionally verified to DGMS Circular No. 3/2010 Category B parameters.
Flat steel bearing plates for standard angular installations. Punched and pressed to DGMS dimensional tolerances and hole diameter specification. Category B compliant.
Heavy-duty steel cog stools used for temporary and permanent roof support in underground mine roadways and intersections. Provides stable load-bearing support between the floor and roof strata.
Steel SHS props with adjustable/variable height mechanism for flexible roof support across varying seam heights in underground workings. Designed for quick setting and reliable load transfer to the roof.
| Parameter | 20 mm Bolt | 22 mm Bolt | 25 mm Bolt |
|---|---|---|---|
| Nominal Diameter | 20 mm | 22 mm | 25 mm |
| Thread Designation | M20 | M22 | M25 |
| Shear Pin Break Torque | 70 - 90 Nm | 90 - 110 Nm | 90 - 130 Nm |
| Available Lengths | 1000 / 1200 / 1500 / 1800 / 2000 / 2400 / 3000 mm | ||
| Steel Grade | Fe 500 / Fe 550 / Fe 600 / Fe 650 | ||
| Governing Standard | DGMS/S&T/Tech. Cir. (Approval) No. 3, Dated 3rd June 2010 | ||
The bolt end is precision taper-cut to a consistent angle, allowing smooth and rapid penetration of resin cartridges during installation. Produces fast, clean mixing in the spin-to-stall cycle.
A proprietary formed end profile providing enhanced grip in softer or fractured rock strata where standard ends may not achieve full resin bond. Suitable for difficult geologies.
The bolt end is hot forged under press to form a mushroom head. Provides maximum mechanical integrity at the resin anchor zone with no material reduction. The standard choice for most coal mine applications.
All orders dispatched in customer-specified packaging. Complete sets shipped with test documentation.
Bolts stacked and secured on heavy-duty metal racks for easy site handling and unloading.
Wire-bound bundles on wooden pallets — suitable for forklift handling and bulk warehouse storage.
W-straps and plates wire-bundled in uniform stacks for space-efficient transport to mine sites.
The installation method used with Manav Engineering resin-grouted roof bolt assemblies.
The bolt is spun to mix the resin cartridge. Spinning continues until the gelling resin increases resistance — causing breakout of the torque nut. The nut then runs up the thread and tightens against the bolt, completing installation.
The length of exposed thread after installation provides a direct indication of the standard of installation — a key field verification point for mine safety officers.
Although the spin-to-stall system gives a simpler underground operation, it is more demanding on roof bolting system components. The resin must provide sufficient time for mixing and bolt insertion, then transform rapidly from a fluid to a set state and develop high bond strength.
The properties of the resin, the roof bolt, the breakout torque of the nut and the shear pin specification are all critical parameters — all of which are governed by DGMS Circular No. 3/2010 and verified on every batch Manav Engineering dispatches.
Send your Bill of Quantities or technical specification: we respond within one working day.
