MS pipe or mild steel pipe is regarded as the most commonly used pipe around the globe but is also the one most inaccurately specified since there are 3 different pipe sizing methods which apply to the very same steel tube — the nominal bore provides you with the trade size, the outside diameter provides you with the qualification for what can be fitted in it, and the wall thickness provides you with the cost, rating in terms of the pressure and also the weight of the pipe being used. Failure to identify the 3rd item rightly plays a role in getting the invoice wrong by 30% without change in the appearance of the pipe.
This page provides the tables you need to work with: the complete MS pipe size and weight chart classified by class, the formulas used to derive every number for checking them, the ANSI Schedule 40 and 80 equivalents, cross-sectional area comparisons and practical advice concerning the ordering process, tolerances and standard lengths that will help you avoid sending the ordered pipe back on the truck.
Quick answer: The weight of mild steel (MS) pipes is established using the formula (OD − wall thickness) × wall thickness × 0.02466. It is estimated that the density of steel is about 7.85 g/cm³. An example would be that mild steel pipes with the nominal bore (NB) size of 4 inches (100 mm) and wall thickness of 4.5 mm will weigh around 12.18 kg/m while the same pipes made of mild steel with heavier wall thickness of 5.4 mm will weigh approximately 14.50 kg/m. The mild steel pipes produced in India follow the requirements established in the IS 1239 part 1 standard according to which the pipe manufacturer should distinguish between light, medium and heavy thickness of pipes represented in different colors. However, imported pipes and pipes used in processes are typically manufactured under the standards contained in the ASME B36.10M schedule 40 and schedule 80. The difference in the weights of different grades of stainless steel pipes compared to mild steel pipes is not significant: stainless steel 304 has a density of 7.93 g/cm³ against carbon steel which density is 7.85 g/cm³. Moreover, the density of aluminum pipes is approximately at the level of 34% of the density of mild steel.
MS Pipe Weight Chart — Full Size Table
The table underneath lists the different sizes of MS pipes falling under the category of 15 mm NB (1/2") to 400 mm NB (16") based on the 3 thickness classes mentioned in IS 1239 Part 1. The outside diameter of the pipes has been defined according to the standards and the wall thickness given here is the one for its respective classes. The weight of the pipe has been calculated on a per meter basis following the formula given in the next section of this article and have been rounded off to two decimal places. Various standard mill tables to which pipe weight is referred may vary even in the second decimal place. Agreements regarding contract terms must be in writing before purchase.
| NB (mm) | Nominal size | OD (mm) | Light t (mm) | Light kg/m | Medium t (mm) | Medium kg/m | Heavy t (mm) | Heavy kg/m |
|---|---|---|---|---|---|---|---|---|
| 15 | 1/2" | 21.3 | 2.00 | 0.95 | 2.65 | 1.22 | 3.25 | 1.45 |
| 20 | 3/4" | 26.7 | 2.00 | 1.22 | 2.65 | 1.57 | 3.25 | 1.88 |
| 25 | 1" | 33.4 | 2.65 | 2.01 | 3.25 | 2.42 | 4.05 | 2.93 |
| 32 | 1 1/4" | 42.2 | 2.65 | 2.58 | 3.25 | 3.12 | 4.05 | 3.81 |
| 40 | 1 1/2" | 48.3 | 2.90 | 3.25 | 3.25 | 3.61 | 4.05 | 4.42 |
| 50 | 2" | 60.3 | 2.90 | 4.10 | 3.65 | 5.10 | 4.05 | 5.62 |
| 65 | 2 1/2" | 76.1 | 3.00 | 5.41 | 3.65 | 6.52 | 4.05 | 7.20 |
| 80 | 3" | 88.9 | 3.20 | 6.76 | 4.05 | 8.47 | 4.75 | 9.86 |
| 90 | 3 1/2" | 101.6 | 3.30 | 8.00 | 4.05 | 9.74 | 4.75 | 11.34 |
| 100 | 4" | 114.3 | 3.50 | 9.56 | 4.50 | 12.18 | 5.40 | 14.50 |
| 125 | 5" | 139.7 | 4.00 | 13.38 | 4.85 | 16.12 | 5.40 | 17.88 |
| 150 | 6" | 165.1 | 4.00 | 15.89 | 4.85 | 19.17 | 5.40 | 21.26 |
| 200 | 8" | 219.1 | 4.50 | 23.82 | 5.40 | 28.46 | 6.30 | 33.06 |
| 250 | 10" | 273.1 | 5.00 | 33.06 | 5.40 | 35.63 | 6.30 | 41.44 |
| 300 | 12" | 323.9 | 5.40 | 42.40 | 6.30 | 49.33 | 7.10 | 55.47 |
| 350 | 14" | 355.6 | 5.40 | 46.62 | 6.30 | 54.25 | 8.00 | 68.58 |
| 400 | 16" | 406.4 | 5.40 | 53.34 | 6.30 | 62.15 | 8.00 | 78.60 |
When you observe that table for a minute, two things will undoubtedly strike you. The first one is the difference in weight between Light and Heavy as 4" is 52% for a pipe that would be hard to distinguish from its appearance, i.e., 9.56 kg/m vs. 14.50 kg/m. The other one is the fact that the smaller sizes become heavier per unit of bore. For example, the weight of 1/2" pipe equals 0.95 kg/m while the weight of 4" one equals only 12 times more despite carrying 16 times cross-sectional area. The explanation for this is the fact that the thickness of the wall does not correspond to the diameter proportionately, and that causes strange results while pricing per ton for the mixed order.
How the Weight Is Calculated
There is a simple formula that will allow you to calculate the weight of steel pipes you would like to purchase. The formula is W = (D – t) × t × 0.02466 where D is outside diameter (in mm) and t is pipe wall thickness (in mm). This simple formula respects the proper weight of the pipe if you use the correct density constant for the respective material.
If the density of the material is known, the formula can be derived and used for any pipe material, not just steel. The cross-section area of the wall is calculated as (π × (D – t) × t) mm2, and that will give us the volume per 1 metre of the pipe in cm3 (cubic centimeters), and weight is calculated simply as density × volume in g.
For example, if the density is known, the weight of steel pipe will be calculated as the following: W = π × 7.85/1000. For stainless, its weight will be W = π × 7.93/1000. For aluminum, W = π × 2.70/1000 and for copper that equals W = π × 8.94/1000.
| Material | Density (g/cm³) | Constant | Weight vs MS |
|---|---|---|---|
| Mild steel / carbon steel | 7.85 | 0.02466 | Baseline |
| Galvanized steel (zinc coated) | 7.85 + coating | 0.02466 + coating weight | +1% to +6% |
| Stainless 304 / 304L | 7.93 | 0.02491 | +1.0% |
| Stainless 316 / 316L | 7.98–8.00 | 0.02507–0.02513 | +1.7% to +1.9% |
| Aluminium | 2.70 | 0.00848 | −65.6% |
| Copper | 8.94 | 0.02809 | +13.9% |
| Brass | 8.50 | 0.02670 | +8.3% |
Let’s take a good example: a 6” MS pipe having an OD of 165.1 mm and a wall thickness of 4.85 mm. Now first we find the ID by subtracting the wall thickness from the OD i.e., (165.1 – 4.85) = 160.25. The next step is multiplying the ID by the wall thickness, which gives us 160.25 × 4.85 = 777.21. The final calculation involves multiplying it by the density of regular MS, which gives us the weight of the MS pipe of 19.17 kg/m, which also falls in line with the given chart.
To calculate pipe weights in tons we have to multiply the length too, so if we buy a 6 m long piece of 6” medium MS pipe, then it would weigh 19.17 × 6 = 115.0 kgs. If we buy 200 pieces (truckload), it gives us a total of 23.0 tons and that is the point where the differentiation between the medium and heavy class pipe is actually put to end because then it becomes a matter of profitability.
What is also important is the fact that the hot-dip galvanization is applied over a zinc layer of 60 – 85 µm thick which corresponds to 600 g/m² at the max level. On big pipes like this it does constitute less that 1% of the whole weight, whereas on the ½” pipe it is about 3-6%. Thus, when you are calculating the price of the galvanized pipe taking into consideration its weight, you should understand that you can not take this amount as free.
Nominal Bore vs Outside Diameter: The Confusion That Causes Wrong Orders
Nominal bore refers to a concept rather than an actual measurement and hence, a 4” pipe will not be found to have a measurement of 4” in any dimension; the outer diameter being 114.3 mm (4.5”). The origin behind this is that in early iron pipe sizing, nominal size referred to measurements of inside diameter regarding standard wall thickness instead of an actual size measurement.
This means that for a 4” pipe taken from two standards, outside diameter will remain the same keeping the inside diameter different. Outside diameter gets fixed while inside diameter changes as per the wall thickness so if you have a fitting that threads or clamps on outer diameter it will fit on both kinds whereas there would be a major impact on characteristics such as flow capacity, lightness and pressure rating.
There is even a third type of sizing known as sanitary stainless tubing that is the preferred method of sizing in many industries including food, beverages, dairy and pharmaceuticals. Sanitary steel pipe has a one inch outer diameter with 1.65mm wall thickness and if the nominal bore is concerned it will be approximately 22mm and do not correlate at all with the one inch MS pipe.The full breakdown of what sizes stainless steel pipe and tube come in covers how the OD-based system maps against nominal bore, and it is the reference to check before writing a bill of materials that mixes the two.
The most basic rule to avoid errors is to quote MS and utility pipes by NB plus wall thickness while sanitary pipes by OD plus wall thickness. Avoid mixing the two methods in one order.
Same Size, Different Material: What Changes
If you alter the material without changing size and wall thickness, the outer diameter remains constant but the weight varies as per density. The table given below highlights one size 2" (60.3 mm outside diameter) with schedule 40 wall thickness of 3.91 mm, demonstrating how the mass shifts across different materials.
| Material | Constant | Weight per metre | Relative to MS | Where it gets used |
|---|---|---|---|---|
| Mild steel (MS) | 0.02466 | 5.44 kg/m | 100% | Water lines, structural, fire fighting, general utility |
| Galvanized (GI) | 0.02466 + zinc | ~5.60 kg/m | ~103% | Potable water, outdoor exposure, sprinkler systems |
| Stainless 304 | 0.02491 | 5.49 kg/m | 101% | Food, dairy, chemical, high-humidity environments |
| Stainless 316L | 0.02513 | 5.54 kg/m | 102% | Chloride exposure, marine, pharmaceutical, aggressive CIP |
| Aluminium | 0.00848 | 1.87 kg/m | 34% | Lightweight structural, HVAC, marine |
| Copper | 0.02809 | 6.19 kg/m | 114% | Potable water, refrigeration, medical gas |
| Brass | 0.02670 | 5.89 kg/m | 108% | Instrumentation, decorative, marine fittings |
One thing that astonishes those who have the instinct to think stainless is too heavy is to find that the weight difference between mild steel and stainless steel pipe of the same dimensions is way below 2%. The real economy here is in dollars per kilogram — usually from four to six times more for stainless steel pipes than for mild steel pipe — and the reasons for choosing stainless steel for piping systems have nothing to do with how heavy it is. People choose stainless steel because it’s easy to wash and because in wet environments mild steel pipe becomes useless within only a few years — whatever the paint quality might be.
As for the 304 versus 316 decision, typically it is determined not by the temperature or pressure of the piping system but by the presence of chloride. 304 is the all-purpose grade holding up well under food and water conditions. As for 316 and 316L, they include molybdenum that gives them good resistance against pitting and crevice corrosion in any chloride-containing environment; hence, all saline solutions, sea air, and aggressive chemicals require the use of 316.If you are specifying for a food plant, the trade-offs are laid out properly in 304 versus 316 stainless steel performance and selection, and the short version is that downgrading to 304 to save money is a defensible decision only if you are certain there is no chloride anywhere in the process.
Schedule 40, 80 and 160: The ANSI System
In situations where your pipe is manufactured abroad or your job follows American design peculiarities, the ASME B36.10M schedule system will be applicable instead of the IS class system. Schedules indicate the thickness of a pipe, but they may be somewhat deceptive — a Schedule 40 for a pipe of 1/2” is 2.77 mm, whilst for a pipe of 24”, this value is 17.48 mm. What goes for schedule numbers is that they belong to the old pressure rating system rather than the measurement system.
| Nominal size | OD (mm) | SCH 40 t (mm) | SCH 40 kg/m | SCH 80 t (mm) | SCH 80 kg/m |
|---|---|---|---|---|---|
| 1/2" (15 mm) | 21.3 | 2.77 | 1.27 | 3.73 | 1.62 |
| 3/4" (20 mm) | 26.7 | 2.87 | 1.68 | 3.91 | 2.20 |
| 1" (25 mm) | 33.4 | 3.38 | 2.50 | 4.55 | 3.24 |
| 2" (50 mm) | 60.3 | 3.91 | 5.44 | 5.54 | 7.48 |
| 3" (80 mm) | 88.9 | 5.49 | 11.29 | 7.62 | 15.27 |
| 4" (100 mm) | 114.3 | 6.02 | 16.07 | 8.56 | 22.32 |
| 6" (150 mm) | 168.3 | 7.11 | 28.26 | 10.97 | 42.56 |
| 8" (200 mm) | 219.1 | 8.18 | 42.55 | 12.70 | 64.64 |
| 10" (250 mm) | 273.1 | 9.27 | 60.31 | 15.09 | 96.01 |
| 12" (300 mm) | 323.9 | 10.31 | 79.73 | 17.48 | 132.06 |
| 16" (400 mm) | 406.4 | 12.70 | 123.30 | 21.44 | 203.60 |
It is important to observe that the outer diameters (OD) are consistent with those identified in the International Standards (IS) table mentioned above in respect of those sizes. For example, 114.3 millimeters for the 4" pipe and 219.1 mm for the 8" pipe give the same readings. This is not a coincidence; the two systems trace their origins back to the same imperial dimensions. Thus, pipes using the IS and ANSI systems can fit very well with each other with regard to outer dimensions (OD).The standards behind each system are set out in more detail in pipeline standards explained, which maps the dimensional, material and testing standards that apply across utility and hygienic piping.
In context, Schedule 160 is used for high-pressure application and creates about double that of Schedule 80 in terms of the wall for small sizes, whereas Schedule 10 and 5 are thin-walled pipes for low-pressure applications as well as drainage where reducing weight is important.
Which Standard Applies to Your MS Pipe
| Standard | Scope | Sizes | Typical use |
|---|---|---|---|
| IS 1239 Part 1 | MS tubes, tubulars and wrought steel fittings | 15–400 mm NB | Indian water, plumbing, structural, general utility |
| IS 3589 | Steel pipes for water and sewage, ERW | 200–2500 mm NB | Water mains, sewage, large-diameter buried lines |
| IS 4270 | Steel tubes for structural purposes | Various | Structural and mechanical applications |
| ASTM A53 | Black and hot-dipped galvanized welded and seamless steel pipe | 1/8"–24" | US general utility, water, steam, air |
| ASTM A106 | Seamless carbon steel pipe for high-temperature service | 1/8"–48" | Process piping, boilers, high temperature |
| API 5L | Line pipe | 1/2"–80" | Oil and gas transmission |
| ASTM A795 | Black and hot-dipped zinc-coated pipe for fire protection | 3/4"–10" | Sprinkler and fire-fighting systems |
When it comes to MS pipes, there are practical differences to note. IS 1239 Part 1 presents the classification system of MS pipes, which is mainly used in India. The IS 1239 Part 1 classifies the MS pipe into different thicknesses, which can be differentiated easily at the mill through color coding. On the other hand, IS 3589 is the standard pertaining to ERW pipes with larger diameter used in the main water and sewage pipeline. The thickness of the water pipes as per IS 3589 comes from pressure formula instead of a standard classification system, and hence, some of the unusual figures sometimes obtained such as 4.85 mm which is not rounded but calculated.
The equivalent of ASTM A53 is an effective comparison for MS pipes sourced from the USA. The A106 is the seamless high-temperature variety of MS pipe; it is expensive. For fire sprinkler pipe system, the applicable standard is ASTM A795 meaning that thickness of wall of pipe remains regulated instead of being selected at will.
Ordering, Tolerances and Standard Lengths
Four fundamental aspects that determine whether a piping order is usable include:
- Standard length. Generally, MS Pipes coming from India have a standard length of six meters, but upon request, it can ship pipes of twelve meters, larger sizes. In the USA, standard lengths for line pipes are twenty-one or forty feet, respectively. If the cutting plan is constructed based on six-meter-long tubes and the mill sends all pipes of five.eight meters in length, it means that the yield is calculated incorrectly, causing the additional purchases.
- Weight tolerance. Pipes can be sold by theoretical or actual weight, which may differ from one another by 5-10%, with the first one determining the dimensions and using the above formula. The actual weight, in turn, is determined upon weighing the pipes. For large orders, this is an important detail that may result in serious money losses. Agree on the weight definition before making the order, as well as check some lengths upon delivery to verify the weight.
- Dimensional tolerance. According to IS 1239, the maximum allowed wall thickness and outer diameter deviation is roughly ±10% Applicable here is a range of own wall thickness values calculated above for pipes with an estimated wall thickness of 4.5 mm, making minimum wall thickness of a pipe equal to 4.05 mm. Such parameter can be used as the weight variation of around this value applied during the production process.
- End finish. Plain end, bevel or thread end, threading or threading and coupling. For small pipelines threaded MS pipes are popular but the fact that they infringe the wall thickness complicates joining the pipes together. Different options are implemented today with regard to join MS pipes but grooved and clamped systems show better results with larger pipes. Choosing the connection method in this case is extremely important since one needs to ensure the diameter, wall thickness, and ferrule parameters match each other.
| Ordering item | What to specify | Why it matters |
|---|---|---|
| Size basis | NB + wall thickness, or OD + wall thickness | Two conventions that are not interchangeable |
| Weight basis | Theoretical or actual | 5–10% of the invoice |
| Length | Fixed or random, and the tolerance | Cutting yield and freight |
| Wall tolerance | Minimum wall if pressure governs | Nominal wall can be 10% under |
| End finish | Plain, bevelled, threaded, grooved | Threading reduces wall at the joint |
| Coating | Bare, painted, galvanized, coating spec | Adds weight and changes corrosion life |
| Test certificate | Mill test certificate to the named standard | Required for pressure and structural work |
Qualifying a Supplier
MS pipe is a commodity, which means that differences between suppliers are in everything but the metal itself. That means that there are no drastic differences between manufacturers in terms of quality of MS pipe and the only thing to consider is other factors, including dimension accuracy, documentation accuracy, delivery reliability, and whether or not the certificate of mill test matches the heat number on the pipe.
These five checks can take a few hours but can save you a lot of time. First, you can get a certificate of mill test and check the heat number on the pipe. Second, measure the thickness of the walls with ultrasonic equipment on at least five pipes. Then weigh the length of the pipe. It is advisable to check in written form the length distribution and tolerance used. Finally, be sure to ask some questions concerning what happens if the shipment comes short, as delivery records would become a point of difference.
For buyers comparing suppliers across the wider stainless and carbon steel market, the same evaluation logic applies and the landscape is covered in the leading stainless steel fittings manufacturers worldwide, which is a useful starting point for understanding how a fittings supplier's scale and certifications compare.
Important to mention here. Eagle manufactures sanitary stainless steel tube, fittings, clamps, and valves that conform to ASME BPE and 3-A hygienic standards. We don’t produce MS pipes, which are the subject of the tables throughout this page. Therefore, if you are designing a sanitary process line in the food, dairy, beverage, or pharma market, we are the right company to contact. On the other hand, if you need the 400 mm MS water main, we can send you the requested table, but we cannot help you with that since it’s not our specialty.
FAQ
How do you calculate MS pipe weight per metre?
The equation used is (OD - wall thickness) × wall thickness × 0.02466; the given measurements have to be in millimetres and the result will be measured in kg/m. The value 0.02466 is the product of π and the density value of carbon steel, which equals 7.85 g/cm³, divided by 1,000. For instance, for 4" made of mild steel with a thickness of 4.5 mm, we get (114.3 − 4.5) × 4.5 × 0.02466 = 12.18 kg/m. If the total weight of a delivery has to be calculated, it is done by multiplying the length of the pipe and the number of pipes in the order. All the calculations described above correspond to theoretical weight, while the practical weight can be different by 5-10% due to rolling deviances, therefore it is important to agree on how the payment is calculated.
What is the weight of a 1 inch and 2 inch MS pipe?
The definition of pipe size depends on the outer diameter of the pipe and it may differ from the nominal size of the pipe. For instance, in the case of 1" (25 mm) pipe, its outer diameter measures 33.4 mm for the different types of pipes. Hence, in the case of Light class, the pipe weighs about 2.01 kg/m, whereas the weight in the Medium class is approximately 2.42 kg/m and in the Heavy class is 2.93 kg/m. Besides that, in the case of 2" (50 mm NB) pipe, the outer diameter is defined as 60.3 mm and this pipe weighs about 4.10 kg/m in Light class and 5.10 kg/m in Medium class and 5.62 kg/m in Heavy class.
What is the difference between Light, Medium and Heavy MS pipe?
According to the Indian Standard IS 1239 Part 1, there exists a classification for pipes known as thickness classes having a common outer diameter but varying wall thickness, thus causing differences in the possible pressures, weights, and prices of the same. Light grade has the slimmest wall and is used for low-pressure applications such as conduits but also for light construction. The pipes in the medium category are considered as generally appropriate for plumbing works, water, and utility applications. Heavy class pipes have the thickest walls and are used in high-pressure applications due to their ability to withstand environmental factors such as mechanical damage, steam, and compressed air. Thickness classification allows one to appreciate the fact that despite the almost identical appearance of heavy and light pipes, the former weighs about 52% more than the latter at 4", which is equal to 14.50 kg/m against 9.56 kg/m.
Does stainless steel pipe weigh more than MS pipe?
It is only marginally heavier, whereas the majority of people probably believe otherwise. If we consider the same outside diameter and wall thickness, both stainless steel 304 and steel 316L are only 1.0% and 1.9% heavier than mild steel, respectively, meaning that the density of the former is 7.93 g/cm³ and 8.00 g/cm³ for steel 316L, in comparison with 7.85 g/cm³ for carbon steel, whereas the weight of a pipe 2" in diameter and 3.91 mm in wall thickness equals 5.44 kg/m in mild steel and 5.49 kg/m in stainless steel 304. Thus, weightwise, these steels are the same, but in terms of price, they differ by four to six times and behave differently concerning corrosion. If we switch to another direction, we will notice that aluminium with density of 2.70 g/cm³ is much lighter than steel by about 34%, while copper with density of 8.94 g/cm³ is heavier than steel.
References
- Bureau of Indian Standards — IS 1239 Part 1 Steel Tubes, Tubulars and Other Wrought Steel Fittings
- Bureau of Indian Standards — IS 3589 Steel Pipes for Water and Sewage
- ASME B36.10M — Welded and Seamless Wrought Steel Pipe
- ASTM International — A53, A106, A795 and API 5L Specifications
- ISO 4200 — Plain End Steel Tubes, Welded and Seamless: General Tables of Dimensions and Masses
- ASME BPE — Bioprocessing Equipment Standard
- 3-A Sanitary Standards — Hygienic Equipment Design Criteria
- ASTM A312 — Seamless and Welded Austenitic Stainless Steel Pipe
Conclusion
On any order for MS pipes, wall thickness is the key number, as it dictates weight, pressure rating and price; and it is the only dimension that cannot be determined visually. The formula (OD − t) × t × 0.02466 gives you the answer to any question regarding a quotation, an estimate of a truckload or a material switch in a matter of seconds, and it works for the three metals provided the constant changes.
Three main things to remember: Clarify the sizing convention prior to preparing the purchase order, since nominal bore is not interchangeable with outside diameter and is responsible for most returns; Know the weight system you will be using, be it theoretical or actual, since a 5–10% tolerance on a big order is a significant amount of money; And when pressure is an issue, ask for the minimum wall thickness instead of the nominal one because legitimate rolling tolerance of 10% could lead to losing important margin of safety. If your order is hygienic, however, you have a different story, as Eagle manufactures sanitary stainless tube, fittings, clamps and valves according to ASME BPE and 3-A standards, which is the only point where we really help and do not just give you a chart.
