What Should Contractors Check When Buying Street Light Poles?

1. Height and section

Height is set by the lighting design, not by the pole catalogue, so agree the mounting height with the luminaire and the road class first. Once the height is fixed, the section follows from the appearance requirement and the mounting detail:

• Round and conical poles — a tapered round section, the most economical option for street and area lighting.
• Octagonal poles — eight-sided, normally on the same dimensional table, with a flatter face for welded arms and signage.
• Square-tube poles — square or rectangular section for architectural streets, car parks and double-arm arrangements.
• Mid-hinged poles — a hinge above the base lets the pole be lowered for maintenance without a crane or a platform.

Ask for the dimensional table in writing, and check that the height you have specified is a standard row or is explicitly listed as a made-to-drawing height. When a pole height is quoted without its top and bottom diameters, the quote cannot be compared with another one.

2. Steel grade and wall thickness

“Street light pole, Q235” is not a specification. The grade determines the allowable stress in the structural calculation, and the wall thickness determines the section modulus that resists the wind moment; a pole that is correct at one grade can be under-strength at another. State the grade — commonly Q235, Q235B or Q345 — and require that it appears on the drawing and on the mill certificate supplied with the order. “Q235 or equivalent” is the phrase that lets a supplier substitute a lighter section after the contract is signed.

Wall thickness is where the real variation hides, because it is the hardest thing to check on a finished pole and the easiest thing to reduce. Put a tolerance on it rather than a nominal figure.

3. The dimensional table you should be given

A conical or octagonal pole quote is only checkable if it carries the section dimensions. As a reference, the table we work from for 6 m to 12 m poles looks like this:

Height H	Wall thickness S (mm)	Top Ø D1 (mm)	Bottom Ø D2 (mm)	Base plate F1 (mm)	Weight F2 (kg)
6 m	2.5 / 3	60–76	135 / 140	280×280×12	55
7 m	2.75 / 3	60–76	150	280×280×12	81
8 m	3	60–76	150 / 160	280×280×12	100
9 m	3.25 / 3.50	60–76	175 / 180	300×300×12 · 340×340×14	118
10 m	3.5 / 3.75	60–75	180 / 190	350×350×12 · 360×360×14/16	146
11 m	3.5 / 3.75 / 4	60–70 / 80	180 / 200 / 210	350×350×16 · 360×360×16/18	165
12 m	3.75 / 4	60–70 / 80	200 / 210	350×350×16 · 380×380×16/18/20	190

Column F2 is the pole weight in kilograms, and it is the fastest sanity check you have: steel is sold by mass, so a quoted pole that is far lighter than the table for its height is either thinner-walled or a shorter section. Weigh one pole on arrival and compare.

4. Tolerances worth writing into the order

Property	Tolerance
External diameter	±1%
Shape	±3% of the diameter
Thickness	±10%
Straightening	±0.3% of total length
Length	±0.5%

These figures matter because a pole that is visibly bowed is obvious, while one that is 8% under thickness is not — and it is the second one that fails in a storm. If your contract has no tolerance clause, the supplier is being asked to meet a nominal number that nobody can check.

5. Base plate, anchor bolts and the foundation

A square base plate is welded to the pole root and drilled for the anchor bolts, with the weld dressed and the whole assembly galvanised. Three questions decide whether that fits your site:

• Who supplies the anchor bolts? If the pole and the bolts come from different sources, nobody owns the fit. Ask for them as one package, with the bolt diameter, embedment depth and thread length stated.
• Is a foundation drawing included? It should show the base plate size, the hole pattern, the bolt projection above the concrete, the concrete grade and the reinforcement. Without it the site team invents a foundation, and the pole’s own wind calculation stops being valid.
• Is there an anchor template? A drilling template that holds the bolts in position while the concrete cures is the cheapest item on the order and the one most often left out. If the hole pattern is out by 10 mm, the pole does not go on.

Agree the door and cable-entry position on the drawing as well. On a two-way road it determines which side of the pole the cable arrives from, and on a hinged pole it decides which way the pole lowers.

6. Wind load — the calculation behind the pole

A pole is a cantilever, and what it resists is the moment created by the wind pressure on everything mounted at the top: the luminaire, its arm, and — on an all-in-one or all-in-two light — the projected area of the head with its solar panel. Two poles that are the same height can therefore need different sections, and the difference is not visible on a quotation.

Ask for the pole design calculation for your local wind speed, and check that it uses the actual projected area of the products you are installing rather than a nominal one. Lighting columns are commonly assessed against EN 40, and fabricated steelwork against EN 1090; where a project cites either, the calculation and the material certificates are the evidence. A supplier who cannot produce a calculation for the specified wind speed is offering a pole that is sized by habit.

7. Galvanising and finish

Hot-dip galvanising is the standard corrosion protection for lighting columns; galvanised plus powder coating to a RAL colour is available where the specification or the client asks for a colour. The number that matters is the coating thickness in microns, not the word “galvanised”. Ask for the galvanising report and the thickness, and relate it to ISO 1461, the standard that defines the minimum coating for fabricated steel. On a coastal or high-humidity site this is the single specification item that decides whether the pole is still sound in year ten.

Check too that the galvanising was done after all welding and drilling. A hole cut into a galvanised pole leaves bare steel, and it will be the first place to rust.

8. The interface to the luminaire

The pole and the light are usually bought on the same order and made by different factories, which is where interface problems start. Agree in writing: the arm height measured from the base plate, the arm type (single or double), the spigot or bracket diameter that the luminaire clamps onto, the arm’s reach and its upward angle, and the position and size of the cable entry into the pole. A flatter face is one reason to choose an octagonal section when arms or signage are welded on.

Then insist on one interface drawing, signed by both suppliers, that shows the pole top, the arm and the luminaire mounting together. That single sheet prevents the most common site failure in a street lighting package.

9. What to check before the poles are packed

Inspection happens at the factory, against the approved drawing, before the container is sealed. The list is short and mechanical:

• Height, top and bottom diameter, and wall thickness — measured, not read off the label.
• Straightness, checked over the full length rather than by eye.
• Base plate dimensions, plate thickness, hole diameter and hole pitch, against the drawing and the anchor template.
• Weld quality and dressing, on the base plate, the shaft seam and the arm.
• Door, cable entry and their positions; the door gasket or cover if one is specified.
• Galvanising thickness, coating appearance, and no uncoated areas at drilled holes or welds.
• Arm height, arm type, spigot diameter and drilling for the luminaire.
• Mill certificate for the steel grade and the galvanising report.
• Quantity, pole weight against the table above, and packing that will survive the sea freight.

Photograph each item as it is checked. A pole that arrives bent is a claim, and a claim is only as good as the evidence that left the factory. Our pre-shipment inspection checklist covers the same principle for the whole system rather than the column alone.

The mistakes that cost the most

• Ordering by height alone. Height does not define a pole; the section, the thickness and the grade do.
• Accepting “Q235 or equivalent”. It is the wording that lets the section be reduced after the contract is signed.
• No wind calculation. A pole sized by habit is sized for somebody else’s site, luminaire and wind zone.
• No anchor template. Cheapest item on the order, most expensive item to fix once the concrete has cured.
• Two suppliers, no interface drawing. Nobody owns the fit between the luminaire and the arm.
• Drilling or cutting after galvanising. Every new hole is a corrosion start point.
• No weight check. The pole weight is the one figure that betrays a thin-walled section, and it takes a minute to verify.

How we can help

We are a China-based trading and project sourcing company, not a manufacturer. We review specifications and BOQs, match a product and configuration to your site conditions, source from qualified manufacturers, and manage quality through to pre-shipment inspection. For poles we work to the dimensional table above and to your drawing, and we can supply the pole, the arm, the anchor bolts and the foundation drawing as one package. If you are preparing a tender or comparing pole quotations and want a second opinion, contact us.