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Galvanized Self-Drilling Anchor Hollow Bars

Corrosion protected Self-drilling anchor hollow bar, in accordance with EN ISO 1461:1999.

Self drilling hollow bar can be protected against corrosion in a variety of ways, suitable for both temporary (<24 months) and permanent (>24 months) applications.

Galvanizing Standards: Self-drilling anchor hollow bar can be protected against corrosion by hot dip galvanizing in accordance with ASTM A-153 or EN ISO 1461:1999.

The coated Zinc is common and relatively cheaper. While the steel is in the kettle, the iron in the steel reacts with the molten zinc to form a tightly-bonded alloy coating that provides superior corrosion protection to steel.

The protective effect of HDG coating on steel is similar to that of sacrificial anode method.

The thickness of zinc coating should be strictly controlled to ensure the specification of threads. In most cases, the female thread dimensions of nut or coupler should be larger than usual. And this may reduce the load carrying capacity.

You can read the technical article Micropile Reinforcing System and Corrosion Protection for further understanding.

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Hot dip galvanizing (HDG) is an universal technology in construction anchoring industry, which is required in high corrosion evriroment. The strength of self drilling hollow bar will be decreased 10% to 20% after HDG, so an effective method is to increase the weight of bar and heat treatment to keep the strength unchanged after HDG. Our technology no need to increase the weight of hollow bar, just use our special technology to increase the bar’s strength 20% to 30% before HDG, so that the HDG bar’s strength will be the same as plain bar.

TECHNICAL DATA

R Thread Hollow Bar (HDG)	R25	R32L	R32N	R32S	R32SS	R38	R51L	R51N
Average Inner Diameter	12.0 mm	21.5 mm	20.5 mm	17.0 mm	15.0 mm	22.0 mm	39.0 mm	34.0 mm
Cross-Sectional Area	230 mm²	304 mm²	365 mm²	440 mm²	520 mm²	519 mm²	700 mm²	900 mm²
Yield Load	150 kN	160 kN	230 kN	280 kN	330 kN	400 kN	450 kN	630 kN
Ultimate Tensile Load	200 kN	210 kN	280 kN	360 kN	400 kN	500 kN	550 kN	800 kN
Yield Stress	650 Mpa	526 Mpa	630 Mpa	640 Mpa	630 Mpa	770 Mpa	640 Mpa	700 Mpa
Ultimate Stress	870 Mpa	690 Mpa	770 Mpa	820 Mpa	770 Mpa	960 Mpa	790 Mpa	880 Mpa
Products Weight	1.80 kg/m	2.60 kg/m	2.90 kg/m	3.40 kg/m	4.10 kg/m	4.00 kg/m	5.60 kg/m	7.00 kg/m
Elongation Agt	> 2.5%	> 2.55%	> 2.5%	> 2.5%	> 2.5%	> 2.5%	> 2.5%	> 2.5%

T Threaded Hollow Bar (HDG)	T30	T40L	T40N	T52	T73	T76L	T76N	T76S	T103
Average Inner Diameter	11.0 mm	20.0 mm	16.0 mm	26.0 mm	35.0 mm	58.0 mm	51.0 mm	44.0 mm	51.00 mm
Cross Sectional Area	408 mm²	636 mm²	790 mm²	1250 mm²	2395 mm2	1610 mm²	1990 mm²	2400 mm²	5100 mm2
Yield Load	260 kN	430 kN	525 kN	730 kN	1435 kN	1000 kN	1200 kN	1500 kN	2660 kN
Ultimate Tensile Load	320 kN	540 kN	660 kN	930 kN	1865 kN	1200 kN	1600 kN	1900 kN	3460 kN
Yield Stress	635 MPa	676 MPa	665 MPa	580 MPa	600 MPa	620 MPa	600 MPa	620 MPa	520 MPa
Ultimate Stress	785 MPa	849 MPa	835 MPa	750 MPa	780 MPa	750 MPa	800 MPa	790 MPa	680 MPa
Products Weight	3.20 kg/m	5.00 kg/m	6.20 kg/m	9.90 kg/m	18.80 kg/m	12.60 kg/m	15.60 kg/m	17.00 kg/m	40.00 kg/m
Elongation Agt	> 2.5%	> 2.5%	> 2.5%	> 2.5%	> 2.5%	> 2.5%	> 2.5%	> 2.5%	> 2.5%

Applocations

Civil Engineering	Underground Mining and Tunneling
1. Pile foundation	1. Stabilization of tunnel portals, trenches, and cut-and-cover areas
2. Slope and embankment stabilization	2. Forepoling
3. Reinforcement of excavation pits and retaining walls	3. Face stabilization
4. Foundation of pylons and wind mills	4. Radial rock bolting
5. Anchorage of avalanche protection structures and noise barriers	5. Roof and rib bolting
6. Injection works	6. Injection works