20mm Thread Bar Bolt

Physical Properties	Minimum		Typical
Yield Strength	500MPa	160kN	550MPa	170kN
Ultimate Tensile Strength	600MPa	185kN	650MPa	200kN
Calculated Shear Strength	120kN		130kN
Standard Elongation	16%		19%
Uniform Elongation			12%
Mass Per Metre			2.47kg
Bar Diameter			20mm
Cross Sectional Area			300mm²
Major Bar Diameter			22.1mm max.
Bar Straightness to AS 1442-1991

General Features

This bolt is hot rolled with deformations that form a coarse left hand thread (10mm pitch) over its entire length.
The thread bar form provides good load transfer properties.
The continuous thread provides a high flexibility in “fragile” ground and blasting conditions as the bolt can be readily re-tensioned.
The thread bar bolt is normally used with chemical anchors (refer to Section F), but can be effectively used with cementitious grouts.
Corrosion protection may be provided by hot dip galvanizing (refer to Section G). Alternative coatings are available by negotiation.
Galvanizing may effect performance.

Installation Guidelines

26-27mm hole diameters are preferred. If larger diameter holes are to be used, refer to "Posimix" bolts on page A1.10.
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 anchors 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’s "Practical Guide to Rock Bolting".

Standard Lengths & Packaging

Standard bolt lengths range from 600 to 3000mm in 300mm increments.
Non-standard requirements are available by negotiation.
Bolts are packaged in bundles.
Bolt fittings, such as nuts, anti-friction washers and dome balls, are normally supplied separate with thread bar bolts.

Notes

Only DSI rock bolt components should be used in order to obtain full performance of the bolt system.
DSI's Mining Products Division is Quality Assured to ISO 9001:2000, Registration No.QAC/R61/0315.

PRINTED December 2006: All dimensions, weights, quantities and specifications are those applicable at the time of publication and may be amended from time to time.