Mills sell galvanized pipe by the ton. Plumbers, contractors and hardware shops buy it by the length. Every importer sits between those two units, and the conversion factor is the weight per metre. Get it wrong by a few percent and the container arrives with fewer pieces than your customers were promised. Below are the BS 1387 figures, how to use them, and what to watch on a quotation.
BS 1387 weight table (black, plain end)
These are the nominal masses from BS 1387:1985 for plain-end black tube. EN 10255, which replaced BS 1387, gives practically the same values for its Medium and Heavy series. Wall thickness is in mm, mass in kg per metre.
| Nominal size | Approx. OD (mm) | Light wall | Light kg/m | Medium wall | Medium kg/m | Heavy wall | Heavy kg/m |
|---|---|---|---|---|---|---|---|
| ½" (15 mm) | 21.3 | 2.0 | 0.947 | 2.6 | 1.21 | 3.2 | 1.44 |
| ¾" (20 mm) | 26.9 | 2.3 | 1.38 | 2.6 | 1.56 | 3.2 | 1.87 |
| 1" (25 mm) | 33.7 | 2.6 | 1.98 | 3.2 | 2.41 | 4.0 | 2.93 |
| 1¼" (32 mm) | 42.4 | 2.6 | 2.54 | 3.2 | 3.10 | 4.0 | 3.79 |
| 1½" (40 mm) | 48.3 | 2.9 | 3.23 | 3.2 | 3.57 | 4.0 | 4.37 |
| 2" (50 mm) | 60.3 | 2.9 | 4.08 | 3.6 | 5.03 | 4.5 | 6.19 |
| 2½" (65 mm) | 76.1 | 3.2 | 5.71 | 3.6 | 6.43 | 4.5 | 7.93 |
| 3" (80 mm) | 88.9 | 3.2 | 6.72 | 4.0 | 8.37 | 5.0 | 10.3 |
| 4" (100 mm) | 114.3 | 3.6 | 9.75 | 4.5 | 12.2 | 5.4 | 14.5 |
| 5" (125 mm) | 139.7 | — | — | 5.0 | 16.6 | 5.4 | 17.9 |
| 6" (150 mm) | 165.1 | — | — | 5.0 | 19.7 | 5.4 | 21.3 |
Light class stops at 4". The class is shown by a colour band on each pipe: brown for Light, blue for Medium, red for Heavy. If you are still deciding between BS 1387 and an American schedule, read our BS 1387 vs ASTM A53 comparison first, because the walls and threads differ.
Galvanized pipe weighs more than the table
The table is for black steel. Hot-dip galvanizing adds zinc on the outside and the inside of the pipe, so a galvanized length is heavier. You can estimate the extra weight yourself:
- Work out the surface area per metre: π × (OD + ID) in metres. For a 1" Medium pipe, OD 33.7 mm and ID 27.3 mm give about 0.19 m² per metre.
- Multiply by the zinc coating mass. At 500 g/m² that is roughly 0.10 kg per metre.
- Add it to the black weight: 2.41 + 0.10 ≈ 2.51 kg/m, about 4% more.
Small sizes gain a larger percentage because they have more surface for each kilogram of steel. Screwed-and-socketed pipe is also slightly heavier than plain end, because of the socket on one end. When a supplier quotes "galvanized, threaded, with socket" and prices per ton, ask which weight basis they used to calculate pieces.
From tons to pieces: a worked example
Suppose a hardware wholesaler in Dar es Salaam orders 25 tons of 2" Medium, 6 m lengths, galvanized.
- Black weight per length: 5.03 × 6 = 30.2 kg
- Estimated zinc per length: surface ≈ π × (0.0603 + 0.0531) × 6 ≈ 2.14 m², × 0.5 kg/m² ≈ 1.07 kg
- Galvanized weight per length: about 31.3 kg
- Pieces in 25 tons: 25,000 ÷ 31.3 ≈ 799 lengths
If you had used the black figure you would have expected 828 lengths, a difference of about 30 pipes. That gap is where many disputes between importers and their own customers start.
Theoretical weight or actual weight?
Pipe is invoiced one of two ways, and the contract should say which:
| Basis | How it works | Who it favours |
|---|---|---|
| Theoretical weight | Pieces × length × nominal kg/m (plus an agreed zinc allowance) | Predictable for both sides; the buyer knows the piece count before loading |
| Actual weight | Bundles are weighed on a scale at the mill or port | Fair if the pipe is on nominal wall; costly for the buyer if walls are at the upper tolerance |
The standard allows a tolerance on wall thickness and mass, so two mills can deliver "2 inch Medium" with different real weights. A pipe rolled on the thin side of the tolerance and sold by theoretical weight means fewer tons of steel for your money; a pipe on the heavy side sold by actual weight means fewer pieces. Ask for the measured wall and the weight of a sample bundle before loading.
Five checks before you accept a quotation
- Class in writing. "BS 1387 pipe" alone is incomplete. Write Light, Medium or Heavy, and the colour band.
- Weight basis. Theoretical or actual, and whether the zinc is included.
- Length. 6 m is standard; 5.8 m fits a 20ft container more easily. Shorter lengths change the piece count.
- Ends. Plain, threaded BSPT, or threaded and socketed, with plastic caps on threads.
- Galvanizing method. Hot-dip galvanized after forming, with a stated minimum coating mass, not pre-galvanized strip.
Our galvanized steel pipe range covers these classes and sizes. For fencing, frames and other non-pressure work, a lighter galvanized round tube is often the cheaper choice.
Frequently asked questions
What is the weight of 1 inch BS 1387 Medium pipe per metre?
2.41 kg/m for black plain-end pipe with a 3.2 mm wall; the hot-dip galvanized pipe is roughly 4% heavier because of the zinc.
How many kilograms is a 6 m length of 2 inch Medium galvanized pipe?
About 30.2 kg black (5.03 kg/m × 6 m), and roughly 31 kg after hot-dip galvanizing, depending on the coating mass.
Are EN 10255 weights the same as BS 1387?
For the Medium and Heavy series they are practically the same, so the BS 1387 table can be used for EN 10255 M and H pipe.
Does BS 1387 Light class come in 5 and 6 inch?
No. Light class covers ½" to 4" only; 5" and 6" are made in Medium and Heavy.
Need a quotation?
Send us the size, grade, quantity and destination port — we reply with a CFR/CIF price, usually within 24 hours.
