Welded steel tubes to EN 10217-1: dimensions, weights and limit deviations

Lengths: what the standard leaves open and what the market supplies

EN 10217-1 does not specify a length. Tubes are supplied in random lengths, whose range is part of the order and is agreed there. Exact lengths with their own limit deviations are possible, but a design that has to be agreed expressly – not the normal case. That is why the drawing on this page carries no length dimension and shows the tube broken off on the right: the length is not a property of the dimension but a matter of the order.

Customary on the market are 6 m and 12 m, partly up to 18 m. That is the standard length that stockholders and mills supply for tubes of this manufacturing process – welded from strip, electrically (EW, HFW), a figure taken from stock programmes, not from the standard. Whoever needs a specific length states it in the inquiry; whoever plans a quantity calculates with it.

The column per 6 m in the tables on this page calculates with 6 m, because that is the round figure within this range. It is a calculation aid and not a commitment: for a different length take the Weight column (kg per m) and multiply yourself.

How weight and limit deviations come about

The weight per metre is a calculation, not a table entry: outside diameter and wall thickness give the cross-sectional area of the tube, times the density of steel of 7.85 kg/dm³. We calculate it to EN 10220 for every dimension in this overview – which is why every row shows a figure and nowhere a dash.

A limit deviation is not a property of the row but a figure that refers to the nominal dimension. Neither for the outside diameter nor for the wall thickness is the ratio the same throughout – the standard grades it by the dimension itself. The row therefore shows the figure that applies to exactly this dimension. We calculate it for every dimension in this overview, so that the row shows the figure and not a percentage that one would still have to apply oneself.

The limit deviations in the rows are those of the electrically welded tubes (EW, HFW). For submerged-arc welded tubes (SAW) the standard carries a row of its own: for the outside diameter, for all sizes ± 0.75 % or ± 6 mm, the smaller value applies; for the wall thickness up to 10 mm ± 10 % or ± 0.3 mm (the greater value), over 10 mm ± 8 % or ± 2 mm (the smaller value).

For tubes over ⌀ 219.1 with more than 10 mm wall thickness both rows coincide – the figure in the table then applies to both processes. Differences exist only up to ⌀ 219.1 (outside diameter: EW/HFW ± 1 % or ± 0.5 mm, the greater value) and for wall thicknesses from 5 to 10 mm (EW/HFW ± 8 % or ± 2 mm, the smaller value; SAW ± 10 % or ± 0.3 mm, the greater value – at 8 mm wall thickness 0.64 against 0.80 mm).

It is recalculated every time this page is rebuilt, row by row. If one does not add up, the page is not built.

Workmanship and testing: what is not a dimension

Not everything that has to be right about a tube is in the dimension table. How high a weld may stand, how round the cross-section has to be, how straight it has to be and how far the strip edges may be offset against each other – that too is part of the workmanship, and at incoming inspection it helps decide whether a delivery is accepted. Added to this is what can be seen on the delivery: the surface, the ends, the marking and the protection on the way to site.

Standard reference for these details: EN 10217-1. What is stated here is the requirement – it is measured on the delivered tube, and where a tolerance class or an option comes into play, it belongs in the order.

From practice: where ordering goes wrong

Welded is not the poorer choice, it is a different one. EN 10217 governs welded tubes, EN 10216 seamless ones. Both carry the same outside diameters, and a dimension alone therefore does not say which tube is meant. Anyone who orders just “⌀ 114.3 × 3.6” gets whatever the supplier considers obvious.

The weld is a feature you can ask about. Whether it is dressed inside and out, how high the bead may stand and whether the offset of the strip edges is limited belongs to the workmanship and not to the dimension – where the pipe is to be internally coated or pigged, that decides more than the diameter does.

The certificate is decided before the order, not after it. An inspection certificate 3.1 to EN 10204 has to be ordered with the material – for a batch already delivered it cannot be obtained afterwards. What the types mean is explained on our page Inspection documents to EN 10204.

What this page does not say

• No material selection. EN 10217-1 carries non-alloy steel grades for room temperature – P195TR, P235TR and P265TR, each in test categories 1 and 2. Which one suits your case is decided by pressure, medium and design – not by the dimension. The materials overview puts the grades in context.
• No design calculation. Diameter and wall thickness do not yield a permissible working pressure. That calculation belongs to plant engineering.
• Only this one standard. Seamless tubes are covered by EN 10216, welded tubes for elevated temperatures by EN 10217-2 and EN 10217-5, stainless ones by EN 10217-7. The overview is on the page Steel pipes.

Related pages

• Steel pipes: designation, standards and selection: the overview of the pipe families, the test categories and the materials – the page this one branches off from.
• Boiler tubes to EN 10216-2: the seamless sister world for elevated temperatures – the same diameters, a different way of making them and different limit deviations.
• Inspection documents to EN 10204: which certificate type is required when – and why it belongs in the order.
• Tolerances and limit deviations: how limit deviations are read and what they say about a component.

How this data is compiled. This page does not reproduce a standard. It shows the dimensions you need for an enquiry, an order and installation – for sizes we supply, checked against documents from manufacturing works and suppliers and against our own range. Each value states what kind of value it is: specified by the standard, calculated by us or customary in the trade. The currently valid standard is binding. It is available from DIN Media or from your national standards body. How we select our sources and keep them up to date: About this knowledge.

Technical basis of this page: DIN EN 10217-1:2019-08 together with EN 10220 for the diameter series and the weight per metre. Weight, inside diameter, water content, cross-sectional area and surface area are calculated by us from outside diameter and wall thickness; the calculation is checked against the data layer on every build of this page.