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
| Dia | Yield strength MPa |
Tensile strength MPa |
Elongation Rate % |
Yielding Load KN |
Tensile Load KN |
Weight Kg/m |
| φ16 | ≧345 | ≧510 | ≧25 | ≧69 | ≧100 | 1.6 |
| φ18 | ≧345 | ≧510 | ≧25 | ≧87 | ≧126 | 2 |
| φ20 | ≧345 | ≧510 | ≧25 | ≧108 | ≧156 | 2.5 |
SCREW-THREAD STEEL 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.
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 Class | Yield Strength, Rel/Mpa | Tensile Strength,(Rm/Mpa) | Elongation after fracture, A/% |
| PSB830 | 830 | 1030 | 7 |
| PSB930 | 930 | 1080 | 6 |
| PSB1080 | 1080 | 1230 | 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, mm | Nominal Cross Section Area, mm² | Theoretical Weight. kg/m |
| 6(6.5) | 28.27(33.18) | 0.222(0.260) |
| 18 | 254.5 | 2 |
| 20 | 314.2 | 2.47 |
| 22 | 380.1 | 2.98 |
| 25 | 490.9 | 3.85 |
| 28 | 615.8 | 4.83 |
| 32 | 804.2 | 6.31 |
| 36 | 1018 | 7.99 |
| 40 | 1257 | 9.87 |
| 50 | 1964 | 15.42 |
| Theoretical weight in this table is according to steel density 7.85g/cmm³. | ||
APPEARANCE
Fully ribbed bar with no longitudinal ribs
PERMISSIBLE TOLERANCES FOR CHEMICAL COMPOSITION OF STEEL PRODUCTS
GB/T 222-2006
Anyang Longteng Heat Treatment Material Co.,Ltd is a professional heat-treating manufacturer. Our high strength rebars and fasteners have super high performance and properties, much higher than standard requriements. More technical information and discussion, please contact us. We will give you reply within 2 working days, with professionals!
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Post time: Jan-02-2019