Walk into any TMT yard in Chennai and you'll see rods labelled Fe 415, Fe 500, Fe 500D, Fe 550, Fe 550D, CRS… and then you'll be asked "ARS, Tata, ISteel or Arun, sir?" Most builders pick by gut feel and end up either overpaying (premium grade for a small house) or risking under-spec (cheap grade for a multi-storey).
Here's how to actually decide.
TL;DR — which grade for what
| Building type | Recommended grade |
|---|---|
| Single-storey home (G+0) | Fe 500 (or Fe 500D for earthquake zones) |
| G+1 to G+3 home | Fe 500D or Fe 550 |
| G+4 and above | Fe 550D |
| Coastal areas (Chennai east of OMR, ECR) | Fe 550D CRS (corrosion-resistant) |
| Heavy commercial / industrial | Fe 550D minimum, often Fe 600 |
What do the numbers mean?
The "Fe" prefix stands for ferrous (iron). The number that follows is the minimum yield strength in MPa (megapascals — a measure of how much load the steel can take before permanently deforming).
- Fe 415: 415 MPa yield strength (older standard, mostly phased out)
- Fe 500: 500 MPa
- Fe 550: 550 MPa
- Fe 600: 600 MPa (specialty / high-rise)
Higher number = stronger steel = you can use less steel for the same load. But higher number also = harder, more brittle. The "D" suffix (Fe 500D, Fe 550D) means improved ductility — the steel bends more before breaking, which is critical for seismic resistance.
"D" grade — why it matters for Chennai
Chennai falls in Seismic Zone III (moderate earthquake risk). Per the current Indian code (IS 1786:2008 onwards), Fe 500D or higher is recommended for any structural use in this zone.
The "D" grade has tighter limits on phosphorus and sulphur impurities, which is what gives it the ductility. Cost difference between Fe 500 and Fe 500D is around ₹1.50–₹2.00 per kg — negligible on a project total. Always pay the extra for the D-grade.
CRS — corrosion-resistant steel
CRS (Corrosion Resistant Steel) has small amounts of copper, chromium, phosphorus and nickel mixed in. Resists rust 2-3× longer than regular TMT.
When you should pay extra for CRS:
- Coastal locations — salt-laden air corrodes regular steel fast. East of OMR, anywhere on ECR, anywhere within 5 km of the coast.
- Below-grade slabs (basement, plinth) in high-water-table areas
- Bathrooms and wet areas if you're using exposed reinforcement
Cost premium: ₹3–₹5 per kg over regular Fe 550D. For a 1000 sqft single-storey home (~3 tonnes), that's ₹9,000–₹15,000 extra. For a coastal home, completely worth it — saves you from rust spalling damage 20 years in.
Brands we stock — and what's different
ARS Steels (Chennai-based) — Our most-ordered brand. Fe 500D and Fe 550D available across all common diameters. SGS-certified. Good consistency across batches. Mill is in Gummidipoondi. Slightly cheaper than Tata for the same grade because of low transport cost.
ISteel — Tamil Nadu manufacturer. Their ISteel XLS range adds copper-nickel-chromium for corrosion resistance. Good mid-premium option for coastal homes. Slightly more brittle than ARS — fine for residential, talk to your engineer for industrial.
Arun TMT — Another TN brand with strong availability. Fe 550D widely used in apartment construction. Comparable to ARS on quality.
Tata Tiscon — National premium. Fe 500D and Fe 550D Super, ribbed for better bond. About ₹5-8/kg more than ARS. Worth it if specs require Tata or if you want the "blue-chip" brand for a marquee project.
See TMT rod sizes available → — minimum order 500 kg per diameter for direct site delivery; smaller can be combined with other items.
Sizes you actually need
For a 1000 sqft G+0 home:
- 8mm: stirrups, distribution bars in slabs — about 800–1000 kg
- 10mm: slab top, secondary reinforcement — about 500 kg
- 12mm: slab main, beam top — about 700 kg
- 16mm: beam main, columns — about 400 kg
- 20mm: only in heavy columns or large beams — 100-200 kg if needed
For G+1, add 1.5-2 tonnes across these diameters.
For G+2 or higher: get an engineer's BOM, don't estimate.
How to verify what you're getting
Tampering is common in the unbranded TMT market — the "Fe 500D" rod you bought may actually be Fe 415 painted over. To avoid this:
- Buy branded only. ARS, Tata, ISteel, Arun, Vizag, JSW. Every legitimate brand stamps grade markings on every rod at regular intervals.
- Check the bundle tags. Every bundle should have a tag with batch number, grade, weight.
- Cross-check on the brand's website. Most have a "verify your TMT" page where you enter the batch number.
- Test 1 in 50 bars. Cut a piece, send to a NABL-accredited lab (₹500-800 per test). Yield strength reports tell you if you got what you paid for.
Pricing (May 2026 — varies daily)
| Grade | Price range (₹/kg, ex-Chennai) |
|---|---|
| Fe 500 | ₹56–₹60 |
| Fe 500D | ₹58–₹62 |
| Fe 550 | ₹60–₹64 |
| Fe 550D | ₹62–₹66 |
| Fe 550D CRS | ₹66–₹72 |
Bulk orders (5+ tonnes) get ₹1-2/kg discount typically. Steel prices move daily with iron ore and scrap — always confirm price the morning of order.
What about used / reclaimed TMT?
Sometimes offered cheap from demolition yards. Don't use for structural members — you have no way to verify yield strength after heat cycles, weathering, or prior load history. Fine for non-structural uses (compound walls, gates, temporary work).
Bottom line
For a Chennai single-storey home: Fe 500D, any of the four brands we stock. Budget around ₹60/kg.
For G+1 or higher, or coastal locations: Fe 550D, ideally CRS if coastal. Budget around ₹65–₹72/kg.
For multi-storey commercial: get a structural engineer's signed BOM. Don't substitute.
All grades stocked and delivered from Suppliable Sholinganallur. WhatsApp us with your steel BOM and we'll quote with same-day delivery for orders placed before 11 am.
Steel team at Suppliable. Browse all products →