33mm Friction Bolt
- -33mm Friction bolt is roll-formed into a C-shaped bolt with a slot by a high tensile steel band, which one end is tapered for easily inserting the bolt into drilling hole. The other end is welded a ring to hold the bearing plate.
- - Provide customers with pull test for Friction Bolt after installation.
- - The friction bolt have passed tests in many mines and have been supplied steadily for several years
- - The friction bolt undergoes very stringent tensile testing to ensure product quality.
33mm Friction Bolt Functions
33mm Friction Bolt is a frictional ground support system. When a friction bolt is inserted into drilling hole with smaller diameter, the slot partially closes and bolt diameter is compressed, which creates radial forces on rock roof surface along the whole length and firmly holds the rock.
33mm Friction Bolt Features&Advantages
Made from high strength steel band
Easy for installation
Simple design,cost saving
Immediate frictional Support in axial and radial
Independent supporting without plate
Available in black,cold galvanizing or hot dip galvanized
33mm Friction Bolt Mechanical Properties
| Technical Data | TRFB33 | TRFB39 | TRFB42 | TRFB47 | |
| Drill hole diameter (mm) | 30-32 | 35-38 | 38-40 | 43-45.5 | |
| Min.Yield strength (kN) | 80 | 90 | 100 | 120 | 135 |
| Min.Tensile strength (kN) | 100 | 120 | 132 | 165 | 180 |
| Typ.Tensile strength (kN) | 120 | 135 | 150 | 180 | 200 |
| Elongation (A%) | ≥20 | ≥20 | ≥20 | ≥20 | |
| Typ.Anchorage (ton/m) | 4-6 | 4-7 | 5-8 | 6-10 | |
| Bearing plate (mm) | 150x150x4 | 150x150x4 | 150x150x4.5 | 150x150x5 | |
33mm Friction Bolt Accessories
Bearing plate,Driver,Pull collar.
33mm Friction Bolt Length & Package
Length:450-3000mm as specified
Package:100pcs — 300pcs each bundle as specified
33mm Friction Bolt Applications
Mines
Tunnels
Slopes
Places where need ground support
How to work
The nature of ground must be evaluated.
Choose the proper bit and drill a hole according to bolt diameter, bolt length, and drilling procedure, and length is at least 150mm longer than length of friction bolt.
Place a plate onto the friction bolt (dome against the ring,tapered end at front).
Friction bolts must be installed as perpendicular to the rock surface.
Put the driver dolly into the bolt and drive friction bolt into the hole until the plate is firmly against the rock surface.
Do not pound on the friction bolt when plate tightly fixes on the rock surface,in order to avoid damage of friction bolt end.
Pull tests shall be performed to determine initial anchorage of the friction bolts after installation.
