TMT Bars 5 min read
How TMT steel is actually billed — and how to check a quotation
If you are counting bars, you are not checking the invoice. Steel is sold by the kilogram, and the chart is public.
Short answer
TMT bar is billed by weight. The nominal mass per metre is fixed by IS 1786 — 0.888 kg/m for 12 mm, 1.580 for 16 mm, 2.470 for 20 mm and so on — and the site rule of thumb d² ÷ 162 lands within a gram of it. Multiply by bar length and bar count and you have the weight your invoice should be built on.
The formula, and the table it comes from
Nominal mass in kg per metre is the diameter squared divided by 162. IS 1786 Table 1 prints the resulting values, and every mill in the country rolls to them. Brand does not change the weight — a 16 mm bar is 1.580 kg per metre whether it says Tata, JSW or Kamdhenu on it.
Bundles are a convenience, not a unit
This market typically bundles 10 bars of 8 mm, 7 of 10 mm, 5 of 12 mm, 3 of 16 mm and 2 of 20 mm; from 25 mm upward bar goes loose. Those counts are a handling convention. If a quoted bundle weight sits well below the chart, ask what the bar actually weighs before you accept the load.
Rolling tolerance is real, and it is bounded
IS 1786 permits actual mass to vary from nominal within a stated band, which tightens as diameter increases. A small variance is normal. A consistent, one-directional shortfall across a whole delivery is not.
Why we quote rather than publish a price
Steel moves daily. A price printed on a website is either stale or padded to cover the risk of being stale. We quote a rate with a stated validity period so you can budget against a number that will still be there when you confirm.
