TL;DR: One ton (1,000 kg) of 8mm TMT steel holds about 211 rods when each rod is 12 metres long. A 12 m length of 8mm bar weighs about 4.74 kg, and 1,000 ÷ 4.74 ≈ 211. Because 211 is calculated from nominal weight, it changes with bar length: ARS's nominal weight chart[1] works out to roughly 208 bars of 8mm per tonne for bars of about 40 ft. Bundle counts vary far more than tonne counts, because each mill packs bundles its own way. Order TMT by weight for each diameter, use the bar count only to work out that weight, and check every delivery on a scale.
How many 8mm rods are in 1 ton of steel?
One tonne of 8mm TMT steel is about 211 rods of 12 metres. The calculation starts from weight per metre. Indian manufacturer ARS lists the nominal weight of an 8mm TMT bar as 0.395 kg per metre[1], which is 8 × 8 ÷ 162, rounded. Multiplied by 12 m, one bar weighs about 4.74 kg, and 1,000 kg divided by 4.74 kg gives 211 bars. Amrit Steels' own weight chart lists the same 4.74 kg per 12 m bar and about 211 bars per tonne.
You can also think of the tonne as a length of steel. At 0.395 kg per metre, 1,000 kg of 8mm bar is roughly 2,530 m long. The bar count is that length divided by the bar length: about 211 bars at 12 m, or about 422 if the yard cuts to 6 m. That means ARS's figure of about 208 does not contradict the 211. ARS's chart assumes bars of about 40 ft, which is roughly 12.2 m, and longer bars mean fewer bars in the same tonne.
A bars-per-tonne figure means nothing unless the bar length is stated next to it.
Every diameter from 8mm to 32mm converts the same way
The method is the same for every size: multiply weight per metre by bar length, then divide 1,000 kg by the result. This table puts Amrit Steels' chart for 12 m bars next to ARS's approximate bars per tonne for bars of about 40 ft[1], so you can see the effect of length in each row. ARS also notes that the D² ÷ 162 formula can differ slightly from approved nominal values because of rounding. That is why two mills sometimes print slightly different bar weights for the same size.
Counts are rounded to the nearest whole bar. Each row turns directly into an order quantity. For example, 50 bars of 16mm at 12 m is 50 × 18.96 kg, or about 948 kg.
A quintal of TMT is one tenth of the tonne count
A quintal is 100 kg, one tenth of a tonne, so every count in the table divides by ten. One quintal of 8mm TMT is about 21 full bars of 12 m. A quintal of 10mm comes to about 13 bars, and 12mm to about 9. These are nominal counts, so a weighed quintal can be a bar or so either side of them.
Why does bar length change the count per tonne?
The tonne is fixed, but each bar gets heavier or lighter with its length, so the count changes. A 40 ft bar is about 12.2 m and a 12 m bar is about 39.37 ft, so ARS advises buyers to confirm the supplied bar length[1] in the quotation and order documents. Some mills chart 40 ft bars and others chart 12 m bars, so you cannot assume one length across Indian suppliers. Amrit Steels supplies TMT in 12 m lengths, and its chart is based on that length.
Weight is the second variable. Steel is rolled to a nominal mass, and the standard allows a band around it.
For 8mm, the band is wide. A 12 m bar at 7% over nominal weighs about 5.07 kg, and at 7% under it weighs about 4.41 kg. A tonne of 8mm could therefore hold anywhere from about 197 to 227 bars. These two figures are worked out from the tolerance; no mill prints them. We have only seen the tolerance table in a manufacturer's reproduction, so the BIS text of IS 1786 is still the authority. Amrit Steels' chart uses the same bands.
A tonne of 8mm TMT is always the same weight, but the number of bars in it is not.
Bundle counts depend on the mill, because no BIS rule fixes them
According to Saluja Gold, BIS does not set a fixed number of rods per bundle[2]. Mills pack to a practical weight range, so the count changes with the diameter and the brand. The same Saluja Gold page says some local mills bundle to a general 90 to 100 kg weight instead of a fixed rod count. The published counts from four Indian manufacturers show how much they differ:
ARS and Radha TMT agree on 10 bars for 8mm and 5 for 12mm, but the published 12mm counts still range from about 5 to 9 bars. Bundle weights differ even when the counts match. ARS gives a nominal 54.168 kg for its five-bar 12mm bundle of about 40 ft bars. Radha TMT gives about 53.3 kg for five 12mm bars and about 47.4 kg for ten 8mm bars. Madhav KRG Group packs heavier bundles, at about 94.8 kg for twenty 8mm bars.
Buyers who compare yards often find counts that disagree. These charts show that this is normal and does not mean a bundle is short. A different count does not prove different quality either. The ISI mark, the test report and the weight per metre do. Bundle make-up varies from mill to mill, but weight per metre is a number you can actually check. Amrit Steels quotes by quantity per diameter and sells by weight, so you never buy by piece count.
Should you order TMT by rod count or by weight?
Order by weight, and use the rod count only to work out that weight. Adukia Industries notes that TMT bars are generally priced by weight[3]. Even a small weight difference becomes a real cost on a bulk order, and ordering in kilograms matches how the bill is raised. ARS adds that a weight chart is for estimation and procurement planning, not structural design[1]. The bar sizes and quantities come from the engineer's drawings, and the chart converts them into a quantity to buy.
Nothing requires you to order by weight. The reason to do it is that steel is billed, delivered and checked by weight. Converting a schedule into an order takes four steps:
- Take the bar count per diameter from the bar bending schedule. A bar bending schedule (BBS) is the engineer's list of every bar in a structure by diameter, shape and length. Add up the full-length bars needed for each diameter, after allowing for laps and cut lengths.
- Confirm the bar length the supplier quotes. A count based on 12 m bars will not convert correctly using a 40 ft chart. Write the length on the order so both sides use the same bar weight.
- Multiply each count by the weight of one bar. Use the 12 m weights in the table above, or the supplier's chart if the length is different. Round each diameter to a practical weight rather than an exact kilogram.
- Send the weight per diameter on the rate form. Amrit Steels' rate form asks for the brand (if the engineer has specified one), the diameters, the quantity per diameter and the site location. For a whole house, you can send the bar bending schedule or structural drawing and the team will work out the quantities.
Say a slab schedule calls for 300 bars of 8mm and 150 bars of 12mm, all at 12 m. That converts to 300 × 4.74 = 1,422 kg of 8mm and 150 × 10.66 = 1,599 kg of 12mm. The order goes out as about 1.42 t of 8mm and 1.6 t of 12mm. Amrit Steels quotes the day's rate for it, and on project supplies, loading, unloading and delivery are free.
A delivery is checked on a scale, not by counting bundles
Counting bundles tells you how many bundles arrived, not how much steel. Saluja Gold's guidance[2] makes the same point: counting bundles alone does not confirm the quantity. It also gives an example where a 1 m cut of 12mm bar weighing 0.890 kg confirms the diameter. Three checks cover most deliveries:
- Weigh the load. Amrit Steels weighs orders on its own weighing machines, and customers can check the same load on a public weighing scale. Compare the scale weight with the weight you ordered for each diameter, not with a bundle count.
- Weigh a 1 m sample of each diameter. One metre should be within the batch tolerance of its chart weight, so an 8mm sample should weigh 0.395 kg, give or take 7%. This is one of Amrit Steels' five on-site checks, which are set out in how to check a TMT bar is genuine and ISI-marked.
- Match the paperwork to the steel. Ask whether the invoice weight is the scale weight or a theoretical weight from the chart, because the two can differ within tolerance. The test report should match the brand, grade and diameter delivered, and how to read a TMT bar test report explains each field.
Checking diameter from a 1 metre sample
The diameter check works the weight formula backwards. Weigh a 1 m cut, multiply the weight by 162 and take the square root. For example, 0.890 kg × 162 = 144.18, and the square root of that is about 12.0, so the bar is 12mm. An 8mm bar at its nominal 0.395 kg gives 0.395 × 162 = 64, which is 8 squared. Amrit Steels works on the principle that the quantity ordered is the quantity that reaches site, and the scale is how you confirm it.
Frequently asked questions
- How many 8mm rods are in 1 ton of TMT steel?
- One ton of 8mm TMT steel holds about 211 rods when each rod is 12 metres long, since a 12 m rod of 8mm weighs about 4.74 kg. For bars of about 40 ft, the ARS chart works out to roughly 208 rods. Within the ±7% batch tolerance for 8mm, a real ton holds about 197 to 227 rods.
- How many bars are in a bundle of 12mm TMT?
- A bundle of 12mm TMT holds about 5 bars at ARS, Radha TMT and Saluja Gold, while Madhav KRG Group packs 9. Saluja Gold states that no BIS rule fixes the count, so the number in a 12mm bundle depends on the mill. Order 12mm TMT by weight and treat the bundle count as the mill's packing choice.
- How many 10mm rods are in a ton?
- A ton of 10mm TMT holds about 135 rods of 12 metres, because each 12 m rod of 10mm weighs about 7.40 kg. The ARS chart gives roughly 133 rods for bars of about 40 ft. The batch tolerance for 10mm TMT is ±7%, so the delivered count per ton can be several rods higher or lower.
- Should I order TMT bars by number of rods or by weight?
- Order TMT bars by weight per diameter, and use the rod count only to calculate that weight. In India, TMT is generally priced by weight, bar length differs between mills, and actual bar weight varies within tolerance. Multiply the rod count from the bar bending schedule by the weight of one bar to get the TMT weight to order.
- How much does a bundle of 8mm TMT weigh?
- A bundle of 8mm TMT weighs anywhere from about 47 kg to about 95 kg, depending on the mill. Radha TMT lists about 47.4 kg for 10 rods, Saluja Gold about 56.88 kg for 12, and Madhav KRG Group about 94.8 kg for 20. The weight of an 8mm bundle depends on how the mill packs it, not on a standard.
- How do I check whether delivered TMT bars are underweight?
- Check delivered TMT bars by weighing the load and a 1 m sample of each diameter. A 1 m cut of 8mm should weigh about 0.395 kg, within ±7%, and a 1 m cut of 12mm about 0.888 kg, within ±5%. Compare the scale weight of the TMT delivery with the weight you ordered for each diameter, never with the bundle count.
Sources
- TMT Steel Bar Weight Chart: 8mm–32mm, 40 ft & Bundle | ARS, ARS Group (ARS TMT) ↩
- How Many Rods Per Bundle? Complete TMT Bar Bundle Weight Calculation, Saluja Steel & Power (P) Ltd. (Saluja Gold) ↩
- TMT Steel Bars: Why Weight Tolerance Matters - AIC, Adukia Industries (AIC) ↩