IS 1786:2008

Fe 550D TMT Steel Bar

550 MPa yield with 14.5% elongation and D-grade chemistry — the grade infrastructure contractors ask for by name.

Mill test certificate Fe 550D

Standard: IS 1786:2008
Yield stress: 550 N/mm² min
UTS: 600 N/mm² min
Elongation: 14.5% min
Carbon max: 0.25%
S + P max: 0.075%
Bend / re-bend: 5d / 6d
Sizes held: 8, 10, 12, 16, 20, 25, 28, 32, 36, 40 mm

Despatch to any site in IndiaHeat no. on every tag

Specification

Fe 550D specification

The premium structural grade — high strength without giving up ductility. 550 MPa yield with 14.5% elongation and D-grade chemistry — the grade infrastructure contractors ask for by name.

Yield strength: 550 MPa min
Tensile strength: 600 MPa min
Elongation: 14.5% min
TS / YS ratio: 1.08 min

Mechanical and chemical requirements for Fe 550D under IS 1786:2008. These are the minimums we test against before a load is released.
Property	Requirement	Why it matters on site
0.2% proof / yield stress	550 N/mm² min	Sets how much load each bar carries, so it drives the steel quantity in your design
Ultimate tensile strength	600 N/mm² min	The reserve above yield before the bar actually breaks
TS / YS ratio	1.08 min	A higher ratio means the structure warns you before it fails
Elongation on gauge length	14.5% min	How far the bar stretches before fracture — this is what lets you bend it on site
Bend test	5d / 6d	No cracking on the outside of the bend at the specified mandrel
Re-bend test	7d / 8d	Catches embrittlement after ageing, which is where cheap bar fails
Carbon	0.25% max	Lower carbon means better weldability and less brittleness
Sulphur	0.040% max	Excess sulphur causes hot shortness and cracking
Phosphorus	0.040% max	Excess phosphorus makes the bar brittle in cold weather
Sulphur + phosphorus	0.075% max	The combined limit is the single best indicator of primary versus secondary steel

Fe 550D weight chart

Sizes of Fe 550D we hold, with nominal sectional area and unit weight. Actual weight is checked on our weighbridge and held inside ±2% of these figures.
Diameter	Area (mm²)	Weight (kg/m)	Per 12 m bar (kg)	Bars per tonne
8 mm	50.3	0.395	4.74	211
10 mm	78.5	0.617	7.40	135
12 mm	113.1	0.888	10.66	94
16 mm	201.1	1.580	18.96	53
20 mm	314.2	2.470	29.64	34
25 mm	490.9	3.850	46.20	22
28 mm	615.8	4.830	57.96	17
32 mm	804.2	6.310	75.72	13
36 mm	1017.9	7.990	95.88	10
40 mm	1256.6	9.860	118.32	8

Where Fe 550D is the right call

Best used for: Skyscrapers, metro viaducts, flyovers, ports, power plants, raft foundations and transfer girders.

Think twice about: Small residential jobs where the price premium is not justified by design savings.

Fe 550D suppliers by city

Every city page carries the local delivery position, lead time and freight note.

Other grades

Compare against the rest

Fe 415415 MPa · 14.5% elong. Fe 415D415 MPa · 18.0% elong. Fe 500500 MPa · 12.0% elong. Fe 500D500 MPa · 16.0% elong. Fe 500S500 (max 625) MPa · 18.0% elong. Fe 550550 MPa · 10.0% elong. Fe 600600 MPa · 10.0% elong. Fe 500 CRS500 MPa · 12.0% elong.

Questions

Fe 550D — common questions

What does Fe 550D mean?

Fe is iron, the number is the minimum yield strength in newtons per square millimetre. Fe 550D therefore yields at no less than 550 N/mm². The D suffix means a tighter chemistry and higher minimum elongation — a more ductile bar at the same strength.

Where is Fe 550D used?

Skyscrapers, metro viaducts, flyovers, ports, power plants, raft foundations and transfer girders.

What is the elongation of Fe 550D?

14.5% minimum on the specified gauge length under IS 1786:2008. Elongation is what lets the bar be bent on site without cracking, and it is the number to check before you accept a cheaper alternative.

Is Fe 550D available in all diameters?

We hold 8, 10, 12, 16, 20, 25, 28, 32, 36, 40 mm in 12 metre lengths. Anything outside that is rolled to order against confirmed tonnage.

What is the minimum order quantity?

Five tonnes for delivered loads. Below that you are welcome to lift from our stockyard directly, and we will still issue the mill test certificate.

How is the price fixed?

Basic rate per tonne, plus GST at 18%, plus freight to your site. We quote the three separately so you can see exactly what you are paying for.

Do you supply mill test certificates?

Yes, with every despatch. The heat number on the certificate matches the tag on the bundle, so it survives an audit.