Cross Section
Ferrite +
Pearlite
Tempered
Martensite
Fe 500D
IS 1786 : 2008 — TMT Rebar Cross Section
Thermo-Mechanically Treated — QST Process
TMT rebar — tempered martensite rim with ferrite-pearlite core · QST process
Mechanical Properties
500MPa
Min. Yield Strength
565MPa
Min. Tensile Strength
Chemical Composition (% by mass, max)
Element Maximum % Significance Carbon (C) 0.25% Strength; lower = better weldability Sulphur (S) 0.04% Lower = better ductility and toughness Phosphorus (P) 0.04% Lower = better cold-bending performance S + P 0.075% Combined impurity limit Carbon Equivalent (CE) 0.42% Weldability indicator; lower = easier to weld
Bend Test Requirements
Test Bar dia ≤ 20mm Bar dia > 20mm Bend test (mandrel dia) 4d 5d Rebend test (mandrel dia) 7d 9d
Standard Sizes and Weights
Diameter (mm) Area (mm2) Weight (kg/m) Weight (kg/12m) 6 mm 28.3 0.222 2.66 8 mm 50.3 0.395 4.74 10 mm 78.5 0.617 7.40 12 mm 113.1 0.888 10.66 16 mm 201.1 1.578 18.94 20 mm 314.2 2.466 29.59 25 mm 490.9 3.853 46.24 28 mm 615.8 4.834 58.01 32 mm 804.2 6.313 75.76 36 mm 1017.9 7.990 95.88 40 mm 1256.6 9.865 118.38
Applications
Earthquake-resistant construction (IS 13920) High-rise buildings in seismic zones III, IV, V Bridges and flyovers Industrial structures Ductile detailing zones Critical structural members Seismic Zone Suitability
Mandatory for seismic zones III, IV, and V per IS 13920:2016. The preferred grade for all earthquake-resistant design in India.
Applicable Standards
IS 1786 : 2008 — High strength deformed steel bars and wires for concrete reinforcementIS 13920 : 2016 — Ductile design and detailing of reinforced concrete structures subjected to seismic forcesIS 456 : 2000 — Plain and reinforced concrete — Code of practice