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FULL THREADED RE BAR, ROCK BOLT, MINING TUNNEL APPLICATION

Rock bolts are widely used for rock reinforcement in mining and tunneling. Our heat-treated rebars have big advantage on yield strength, tensile strength and pre-stress, which could help to support underground tunnels, roof support.



 

Steel grade:  20MnSi

DiaYield strength
MPa
Tensile strength
MPa
Elongation Rate
%
Yielding Load
KN
Tensile Load
KN
Weight
Kg/m
φ16 ≧345 ≧510 ≧25 ≧69 ≧1001.6
φ18 ≧345 ≧510 ≧25 ≧87 ≧1262
φ20 ≧345 ≧510 ≧25 ≧108 ≧1562.5

 

 

SCREW-THREAD RE BARS FOR PRE-STRESSING OF CONCRETE

The bar portion of rock bolt, is called as screw-thread steel bars, mostly applying for pre-stressing of concrete, which has dis-continuous threads with high strength, high precise, and can be anchored directly by nuts or internal threaded connectors/coupler. <br>



We divide the fully thread bars by the yield strength – Code PSB + minimum yield strength(eg: PSB830). P, S, B represent Prestressing, Screw-thread, bars, and 830 means this rebars’ standard yield strength is 830 MPa. 

 

 

Strength ClassYield Strength, Rel/MpaTensile Strength,(Rm/Mpa)Elongation after fracture, A/%
PSB83083010307
PSB93093010806
PSB108010801230

6

 

 

TOLERANCES

Nominal diameter range : 18 ~50 mm

25mm, 32mm is the mostly common diameters. 

Rebar lengths are often fixed according to orders. Length tolerance is 0~+50mm; Cutting length tolerance is 0~+20mm;

Curving degree shall be less than 0.4% rebar’s total length, and less than 4mm per meter.

top ends must be flat and smooth, to ensure nuts or connectors/coupers passing through.

Nominal Diameter, mmNominal Cross Section Area, mm²Theoretical Weight. kg/m
6(6.5)28.27(33.18)0.222(0.260)
18254.52
20314.22.47
22380.12.98
25490.93.85
28615.84.83
32804.26.31
3610187.99
4012579.87
50196415.42
Theoretical weight in this table is according to steel density 7.85g/cmm³.