Fibreglass Dowel

Threaded & Ribbed FRP Dowels

Physical Properties	12.5 Tonne Dowel	15 Tonne Dowel	20 Tonne Dowel	30 Tonne Dowel	38 Tonne Dowel
Ultimate Tensile Strength	125 kN	150 kN	200 kN	300 kN	380 kN
Nut/Thread Tensile Strength	55 kN	85 kN	85 kN	95 kN	95 kN
Single Shear Strength	45 kN	50 kN	57 kN	65 kN	74 kN
Nut Breakout Torque	30 ft/lbs	35 ft/lbs	40 ft/lbs	40 ft/lbs	40 ft/lbs
Mass per Meter (Std-HD)	650-800 gms	675-850 gms	720-875 gms	750 gms	775 gms
Nominal Bolt Diameter	20 mm	20 mm	20 mm	20 mm	22 mm
Nominal Cross Sectional Area of Bolt	310 mm²	310 mm²	310 mm²	310 mm²	325 mm²
Thread Length	150 mm	200 mm	200 mm	200 mm	200 mm
Major Bar Diameter (thread)	25.4 mm	25.4 mm	25.4 mm	25.4 mm	25.4 mm
Specific Gravity (grams/cm³)	1.7-2.0	1.8-2.1	1.9-2.15	1.95-2.2	2.0-2.25

Notes - HD - High Density Version - 20 and 22 mm bolt diameters available

The dowels are pull formed (matched die) fibreglass construction and are ribbed over its full length to provide maximum load transfer.
Thread form is of a sinusoidal type, nominally 150mm long and 25mm diameter, and is fitted with an integral drive nut with radial face.
All fibreglass dowels are designed to be used with chemical anchors and be fully encapsulated.
Bolts over 2400mm in length are available in all dowel types by negotiation.
Australian Patent Numbers 631881 and 65494 are applicable to these bolts.

26-27mm hole diameters are preferred. Holes over 28mm diameter are not recommended.
Hole depth is critical. Hole depth should be shorter than the bolt to allow for the height of the washer and nut.
After insertion of the chemical anchors, the bolt is rotated through the anchor(s) while being pushed to the back of the hole.
It is important to follow the chemical manufacturer’s recommended mixing and hold times as printed on the chemical anchor cartons. DO NOT OVER MIX.
For further details regarding installation procedures refer to DSI Underground’s "Practical Guide to Rock Bolting".