When constructing buildings in Nepal—a region prone to seismic activity—the choice of TMT (Thermo-Mechanically Treated) bars is critical. Among the grades available, Fe500, Fe500D, and Fe500E are frequently discussed. This blog post breaks down their differences, strengths, prices, and applications, with a focus on Nepal’s market.
1. Overview of TMT Bar Grades
TMT bars are classified based on their yield strength (measured in MPa) and ductility. The prefix “Fe” denotes iron, while the numbers (e.g., 500) indicate the minimum yield strength. The suffix letters (e.g., “D” or “E”) signify enhanced properties like ductility.
- Fe500: Standard grade with high tensile strength.
- Fe500D: Enhanced ductility for earthquake resistance.
- Fe500E: While not widely covered in available sources, “E” might denote even higher ductility than “D.” However, this grade is not standardized in Nepal’s market as per current data.
Note: Fe500E is not discussed in the provided sources. For accurate specifications, consult local manufacturers.
2. Key Differences Between Fe500 and Fe500D
a. Mechanical Properties
| Property | Fe500 | Fe500D |
|---|---|---|
| Yield Strength | 500 MPa | 500 MPa |
| Tensile Strength | ≥545 MPa | ≥565 MPa |
| Elongation (%) | 12% | 16% |
- Ductility: Fe500D’s higher elongation (16%) allows it to bend without breaking, making it ideal for earthquake-prone zones like Nepal .
- Tensile Strength: Fe500D offers ~2% higher tensile strength, enhancing load-bearing capacity .
b. Chemical Composition
| Element | Fe500 (Max %) | Fe500D (Max %) |
|---|---|---|
| Carbon | 0.30 | 0.25 |
| Sulphur | 0.055 | 0.040 |
| Phosphorus | 0.055 | 0.040 |
| S+P Total | 0.105 | 0.075 |
Lower carbon, sulfur, and phosphorus in Fe500D improve weldability and corrosion resistance, while reducing brittleness .
c. Applications
- Fe500: Best for general construction (e.g., bridges, high-rises) where high strength is prioritized over flexibility .
- Fe500D: Preferred for seismic zones, residential complexes, and projects requiring complex bending (e.g., earthquake-resistant structures) .
3. Price Comparison in Nepal
While exact 2025 prices are not listed in the sources, here’s an overview based on historical data and market trends:
- Fe500: ~NPR 120–130 per kg (approx. NPR 120,000–130,000 per tonne) .
- Fe500D: ~NPR 125–135 per kg (slightly higher due to advanced properties) .
Factors affecting price:
- Brand reputation.
- Diameter (e.g., 8mm vs. 32mm).
- Import costs (if sourced internationally).
4. Popular Brands in Nepal
- Jagdamba Steels: Offers Fe500D TMT bars in sizes up to 40mm, emphasizing earthquake resistance .
- Laxmi Steels: Markets both Fe500 and Fe500D, with ribbed designs for better concrete bonding .
- Sree Metaliks (India-based): Known for Fe500D’s controlled manufacturing process, though availability in Nepal may vary .
5. Why Fe500D is Recommended for Nepal?
Nepal falls in seismic zones 4–5, where ductility is critical. Fe500D’s elongation (16%) and lower impurities make it 25% more flexible than Fe500, reducing collapse risks during earthquakes .
6. Choosing the Right Grade
- Residential Projects: Opt for Fe500D for safety in seismic areas.
- Commercial/Industrial: Fe500 suffices for non-seismic regions.
- Cost vs. Safety: Fe500D’s ~5% higher cost is justified for long-term resilience .
Conclusion
While Fe500 remains a cost-effective choice for standard projects, Fe500D is Nepal’s go-to for earthquake-resistant construction. Always verify certifications (e.g., IS 1786) and prioritize brands with rigorous testing facilities. For Fe500E, consult local suppliers for updated specifications.
Build wisely—your choice of TMT bars determines a structure’s lifespan and safety.
References: Data synthesized from industry reports and manufacturer specifications . For precise pricing, contact local distributors like Jagdamba Steels or Laxmi Steels.
