Street Light Poles: Materials, Sizes, Wind Design and Specification
How to choose and specify a street light pole: steel, aluminium, fibreglass and concrete, shapes, wall thickness, wind loads, galvanising, foundations and a specification table.
Key points
- Hot-dip galvanised steel is the standard street light pole: strong, economical and long-lasting; aluminium is lighter and corrosion-resistant but costs more.
- Specify the mounting height, arm length, luminaire weight and wind area, and the design wind speed; the pole size follows from these.
- Galvanising to ISO 1461 or ASTM A123, with powder coating on top for coastal sites, protects the pole for decades.
- The foundation and anchor bolts are part of the pole design, not an afterthought.
The pole is the part of a street lighting project that buyers think about least and pay for heavily if it goes wrong. A pole that is too light bends or cracks in a storm; one that rusts at the base fails without warning; one with the wrong bolt pattern cannot be fixed to the foundation already poured. This guide covers what a street light pole is made of, how it is sized and what to put in the specification.
Materials
| Material | Strengths | Weaknesses | Typical use |
|---|---|---|---|
| Hot-dip galvanised steel | Strong, economical, long life, easy to fabricate | Heavy; zinc wears faster in salt air | The default for roads worldwide |
| Galvanised steel + powder coat | Colour, extra corrosion protection (duplex system) | Higher cost; coating must be done after galvanising | Cities, coastal roads, decorative streets |
| Aluminium | Light, naturally corrosion-resistant, no painting needed | More expensive; less stiff, so larger sections | Coastal areas, pedestrian areas, decorative |
| Fibreglass (GRP) | Very light, non-conductive, no corrosion | Lower stiffness; UV ageing of the surface | Residential, sites needing insulation |
| Concrete | Durable, low maintenance, heavy | Very heavy to transport and lift | Some national road networks |
For most road projects, galvanised steel is the right answer. Choose aluminium or a duplex system near the sea or in industrial atmospheres.
Shapes
- Conical (round tapered): the most common modern shape, rolled from one plate and welded along its length. Clean appearance, good strength for its weight.
- Polygonal (octagonal or dodecagonal): pressed from plate into flat facets; very common for larger poles and high masts.
- Stepped (swaged): sections of round tube of decreasing diameter joined together; traditional in some markets.
- Decorative: cast bases, fluted shafts and ornamental arms for town centres and historic streets.
Typical sizes
| Mounting height | Top / bottom diameter | Wall thickness | Base plate | Anchor bolts |
|---|---|---|---|---|
| 6 m | 60–70 / 130–150 mm | 3 mm | about 260 × 260 × 14–16 mm | 4 × M16–M20 |
| 8 m | 60–70 / 150–170 mm | 3–3.5 mm | about 300 × 300 × 16–18 mm | 4 × M20 |
| 10 m | 70–80 / 180–200 mm | 3.5–4 mm | about 350 × 350 × 18–20 mm | 4 × M20–M24 |
| 12 m | 80–90 / 200–220 mm | 4–5 mm | about 400 × 400 × 20–25 mm | 4 × M24 |
These are typical values for moderate wind speeds and a single luminaire. Heavier loads, double arms, solar panels or higher wind speeds need thicker walls, larger diameters and bigger bolts. The steel is usually a structural grade such as Q235 or Q355 (Chinese grades, comparable to S235 and S355 in Europe). To choose the height itself, see how tall are street lights.
Wind design
Wind is the main load on a street light pole. The force depends on the wind speed squared, the area of everything on the pole (luminaire, arm, panel, signs, banners) and the height at which it acts. A useful way to see it:
- Doubling the wind speed quadruples the force.
- A luminaire or panel at the top of the pole acts on the longest lever, so its area matters most.
- Solar panels are large: a 150 Wp panel is about 0.7 m², several times the area of the luminaire. A solar pole needs a stronger shaft and a larger foundation than a grid pole of the same height.
- Additions such as banners, CCTV cameras, signs and Christmas decorations add area that the original design may not include. Check before adding them.
Give your supplier the design wind speed for the site (from the national wind code, for example EN 1991-1-4 in Europe or ASCE 7 in the US) and the full list of equipment on the pole. The supplier should then provide a calculation of the stresses in the shaft, base plate, welds and anchor bolts.
Corrosion protection
- Hot-dip galvanising after fabrication, to ISO 1461 or ASTM A123. ISO 1461 requires a minimum average zinc thickness of 85 µm on steel thicker than 6 mm (less on thinner steel); many specifications ask for 85 µm or more on the whole pole.
- Inside and outside: galvanising by dipping protects the inside of the pole too, which matters because condensation forms there.
- Duplex systems: a powder coat over the galvanising adds colour and extends life considerably in coastal or industrial air.
- The ground line is where poles fail first: water, soil, salt and dog urine concentrate there. A sealed base, a concrete plinth or an extra coating at the ground line helps.
Doors, cable entries and earthing
- A service door about 0.5–1 m above the ground, with a tamper-resistant lock, for the cable connection, fuse or terminal block.
- A gear tray behind the door for the terminal block and any surge protector.
- A cable entry slot below ground level or through the base plate.
- An earthing point inside the door.
The foundation
The pole and foundation are one design. Typical elements:
- An anchor bolt cage of threaded bolts welded to rings, cast into the concrete.
- A template to hold the bolts in the right pattern while the concrete sets.
- A concrete block or pile, sized for the overturning moment and the soil strength.
- Levelling nuts under the base plate and top nuts tightened to the specified torque.
- A grout or cover over the base plate to keep water out.
Indicative foundation depths are 0.8–1.5 m for 6–10 m poles in normal soil, but always use the supplier’s or engineer’s design for the site.
A specification table you can copy
| Item | Specification |
|---|---|
| Mounting height | [6/8/10/12] m above finished ground |
| Shape | Conical or polygonal, tapered |
| Material | Steel, grade [Q235/Q355 or S235/S355] |
| Wall thickness | [value] mm, per wind calculation |
| Arm | Single / double, length [m], angle [5–15]° |
| Load at top | Luminaire [kg], wind area [m²]; solar panel [Wp, m²] if any |
| Design wind speed | [value] m/s, per [national code] |
| Base plate and bolts | [size] mm plate, [4 × M20/M24] bolts, bolt circle [mm]; anchor cage and template supplied |
| Corrosion protection | Hot-dip galvanised to ISO 1461, average ≥ [85] µm; optional polyester powder coat, colour [RAL] |
| Door and fittings | Lockable service door, gear tray, earthing point, cable entry |
| Documents | Drawing, wind calculation, galvanising certificate, foundation drawing |
Spacing and layout
The pole height also sets the spacing between poles, usually about 3–3.5 times the mounting height. Check your road in our pole height and spacing calculator, which also chooses one-sided, staggered or opposite layouts from the road width and pole height.
We supply complete sets: luminaire, pole, arm and anchor bolts, and for solar projects the panel bracket and battery box. Send us the road details and the wind speed, and we will include the pole drawing and calculation with the quotation. See our LED street lights and solar street lights.
Sources
Frequently asked questions
What are street light poles made of?
Most are hot-dip galvanised steel. Aluminium poles are used where light weight and corrosion resistance matter, for example in coastal and decorative installations; fibreglass where electrical insulation or very low weight is needed; and concrete in some countries for durability and low maintenance.
How thick is a street light pole?
Steel street light poles typically have walls of 3–5 mm. A 6–8 m pole is usually 3–3.5 mm thick, a 10–12 m pole 3.5–5 mm, depending on the wind speed and the load on top.
How deep is a street light pole foundation?
Typically 0.8–1.5 m for poles of 6–10 m in normal soil, but the depth and size must come from a design for the actual wind speed, soil and pole load.
What should a street light pole specification include?
Height, shape, material and steel grade, wall thickness, base plate and anchor bolt details, arm length and angle, design wind speed, the luminaire's weight and wind area, galvanising standard and thickness, any paint finish, door and cable entry details, and earthing.