Flagpole materials: galvanised steel, metal, wood and plastic
Published Written by Flagpole Guides
This page is an English translation of the Portuguese original. Where the two versions differ, the Portuguese text is the original.
The material of a flagpole decides how well it stands up to wind, sun and humidity, and how much it weighs in transport and on the foundation. For outdoor poles, the Brazilian manufacturers consulted work with steel, protected by hot-dip galvanising; for indoor poles, the materials vary more. This guide compares these materials on the basis of the technical sheets.
Hot-dip galvanised steel
B&B Iluminação’s datasheet describes a telescopic pole of SAE 1010/1020 carbon steel tubes, with a 2.0-millimetre wall, hot-dip galvanised, that is protected by dipping in molten zinc. According to the sheet, this pole withstands sun, rain and salt air without rusting, and durability varies with the installation environment. The manufacturer gives a 10-year warranty on the galvanising.
The weights in the same sheet give an idea of the material: from about 23 kilograms for a 6-metre embedded pole to about 67 kilograms for a 12-metre one, with a variation of 5% depending on manufacture. The guide to flagpole transport covers handling these weights.
The ABNT standards
B&B Iluminação lists the Brazilian technical standards on which it relies:
- NBR 6123: wind forces on buildings;
- NBR 6323: hot-dip zinc-coated steel products;
- NBR NM 87: carbon and alloy steels for mechanical construction;
- NBR 8800: design of steel structures, as the calculation reference.
NBR 6123 also appears in the sheet for Metalsinter, published on AECweb, according to which its tubular and polygonal poles are designed to withstand winds of up to 160 km/h. Wind load is covered in the guide to flagpole safety.
Salt air
On the coast, salt-laden air speeds up the corrosion of metals. Hot-dip galvanising is the protection B&B Iluminação gives for these conditions, with the proviso that durability depends on the environment. Small damage to the coating, such as scratches from transport or assembly, exposes the steel; the guide to flagpole repair covers such cases, and the guide to flagpole maintenance regular inspection.
Fittings
The hoisting fittings also have their own materials. In B&B Iluminação’s sheet, the cleat for tying the line is of 1 by 1/8-inch flat iron, welded to the tube, the 125-millimetre guide washer is welded directly to the shaft, and the 2½-inch pulley has a V groove for a braided line. The guide to flagpole accessories presents these parts.
Wood, metal and plastic indoors
For indoor poles, in panóplias and pedestals, the Memorial of the Public Prosecutor’s Office of Minas Gerais describes poles that may be simple stands of wood, metal or plastic. The Memorial’s own poles have an aluminium finial in the shape of a spearhead, 16 centimetres high. Indoors, without direct sun or rain, the material matters less for durability than for appearance and weight.
Summary
| Material | Use in the sources | What the sheets say |
|---|---|---|
| Hot-dip galvanised steel | Outdoor poles of 6 to 12 m (B&B Iluminação) | Withstands sun, rain and salt air; 10-year warranty on the galvanising |
| Metal, wood or plastic | Poles of panóplias and pedestals (MPMG) | Simple stands for indoor flags |
| Aluminium | Spearhead finial (MPMG) | 16 cm high |
The guide on the price of a flagpole covers what the material means for the final price.
Frequently asked questions
Why are outdoor flagpoles made of galvanised steel?
Hot-dip galvanising, dipping steel in molten zinc, protects the steel against corrosion. According to B&B Iluminação’s datasheet, a hot-dip galvanised pole withstands sun, rain and salt air without rusting, and durability varies with the installation environment.
Which ABNT standards do manufacturers cite?
B&B Iluminação’s datasheet cites NBR 6123, wind forces on buildings; NBR 6323, hot-dip zinc-coated steel products; NBR NM 87, carbon and alloy steels for mechanical construction; and NBR 8800, design of steel structures, as the calculation reference.
Does a galvanised steel pole come with a warranty?
It depends on the manufacturer. B&B Iluminação gives a 10-year warranty on the galvanising in its datasheet. Under the Consumer Protection Code, a contractual warranty is in addition to the legal one and is given in writing.
What are indoor poles made of?
According to the Memorial of the Public Prosecutor’s Office of Minas Gerais, the poles of panóplias may be simple stands of wood, metal or plastic. The Memorial’s own poles have an aluminium finial in the shape of a spearhead.
Does salt air affect the pole?
Yes. The salty air of the coast speeds up the corrosion of metal. Hot-dip galvanising is the protection B&B Iluminação gives, describing its pole as resistant to sun, rain and salt air, with the proviso that durability varies with the environment.
Sources
This guide is based on the following sources, most of them in Portuguese:
- Datasheet Mastro para Bandeira – B&B Iluminação
- Mastros Metalsinter – AECweb
- Panóplia – Memorial do Ministério Público de Minas Gerais
- Lei nº 8.078, de 11 de setembro de 1990 (Código de Defesa do Consumidor, artigo 50) – Presidência da República
Related guides
- Types of flagpolesThe types of flagpoles used in Brazil: poles in the ground, embedded or flanged, telescopic and polygonal, lines of poles, façade poles and panóplias.
- Flagpole lifespanHow long a flagpole and a flag last in Brazil: galvanising and environment, sun and wind, the end of a flag’s life and burning on Flag Day.
- Flagpole maintenanceMaintaining a flagpole: line, pulley and cleat, galvanising and salt air, the base and the good condition the law requires of the flag.
- Price of a flagpoleWhat determines the price of a flagpole in Brazil: height, steel, fixing, fittings, foundation, permit, transport and consumer rights.