A process approved by the Government of India for Fe 550 grade bars — rapid, uniform quenching hardens each bar's surface, then atmospheric cooling tempers it from within.
01
Rapid Quenching
As the bar exits the rolling line, its surface temperature is reduced rapidly and uniformly around the full periphery — transforming the outer layer to hard austenite-to-martensite structure while the core stays hot.
02
Self-Tempering
Residual heat still trapped in the bar's hot core migrates outward, tempering the hardened rim into tough, ductile tempered martensite — without any external reheating step.
03
Atmospheric Cooling
The bar finishes cooling in open air on the cooling bed. The core forms a ferrite-pearlite structure — giving the finished bar a hard, strong rim wrapped around a soft, ductile core, in one continuous pass.
Metallurgical Phase Path
Austenite
Martensite
Tempered Martensite
Ferrite / Pearlite
Cooling chamber → cooling plate — surface hardens while the core stays tough. Result: 14% higher minimum elongation than the standard process.
Rib Bonding Technology
A path-breaking rib pattern for unmatched bonding
Unlike conventional parallel ribs, Dwaraka TMT ribs are carved at a precision angle derived from in-house research — creating a stronger steel-to-concrete bond and a straighter, rounder bar throughout its length.
At Dwaraka, we have implemented elaborate and exhaustive quality assurance systems at every juncture of the manufacturing process — through diligence, discipline and by motivating our team to imbibe a culture of the highest standards.
Universal Testing MachineMeasures yield strength, tensile strength and elongation
SpectrometerConfirms precise chemical composition of every heat
Bend & Rebend MachineVerifies ductility and bendability to IS 1786
Compression Testing MachineChecks compressive strength of material samples
Sartorius Moisture AnalyserChecks moisture in raw material for process control
Bomb CalorimeterCalorimetric analysis for input quality control
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Mechanical, chemical and tolerance data for every diameter.
DWARAKAIRON INDUSTRIES