Traffic Signal Pole Galvanizing and Corrosion Protection Standards
Introduction
A traffic signal pole in a coastal city, an industrial zone or a road-salt belt will corrode if not properly protected. Galvanizing and paint systems determine how long the pole survives. This guide covers the standards that govern pole corrosion protection.
Hot-Dip Galvanizing
ISO 1461 (international) and ASTM A123 (US) specify hot-dip galvanizing of steel products. The pole is dipped in a bath of molten zinc at 450°C, forming a zinc-steel alloy layer bonded to the steel. The coating thickness is typically 85-100 microns.
Service life in different environments:
- Rural inland: 50+ years
- Urban inland: 30-50 years
- Industrial (pollution): 20-30 years
- Coastal (salt air): 15-25 years
- Severe marine (offshore splash zone): 10-15 years
GAOQIAO supplies hot-dip galvanized poles to ISO 1461 with documented coating thickness certificates.
Powder Coating over Galvanizing
For harsh environments, add a polyester powder coat over the galvanizing. The powder coat is 60-100 microns thick and provides a colour plus an additional corrosion barrier. Typical service life with powder coat over galvanizing:
- Coastal: 25-35 years
- Severe marine: 15-20 years
GAOQIAO supplies powder coat over galvanizing in RAL colours (yellow, green, black, grey) on request.
Field Cuts and Damage Repair
Any field cut or weld damages the galvanizing. Repair with:
1. Clean the cut back to bright metal 2. Apply zinc-rich repair paint (95% zinc in the dry film) 3. For powder coat over galvanizing: prime with zinc-rich primer, then apply compatible top coat
GAOQIAO ships touch-up paint with every pole order.
Stainless Steel Alternative
For severe marine environments, 316L stainless steel is an alternative to galvanized steel. Cost is 2-3x galvanized, but service life is 40+ years in marine splash zones. GAOQIAO supplies stainless hardware (bolts, brackets) as standard; full stainless poles on request.
Featured Products
GAOQIAO supplies signal poles with hot-dip galvanizing per ISO 1461, optional polyester powder coat, and stainless hardware. See the pole selection guide.
Conclusion
Hot-dip galvanizing per ISO 1461 gives 15-50 years of service depending on environment. Add powder coat for harsh environments. GAOQIAO supplies poles with documented coating certificates. Send us your site environment and we will recommend the right finish.
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Frequently Asked Questions
How do I check the galvanizing thickness?
With a magnetic coating thickness gauge. GAOQIAO supplies thickness reports with each pole.
Can a corroded pole be repaired?
Light surface rust can be wire-brushed and touched up with zinc-rich paint. Heavy corrosion with section loss requires pole replacement.
What colour is standard?
Galvanized steel is silver-grey. Yellow or green are common colour codes for traffic signal poles. GAOQIAO supplies any RAL colour.
Relevant GAOQIAO products
These public GAOQIAO catalogue pages are related to the guide. Open them for the representative description, then confirm the latest drawing and configuration before ordering.
- Traffic signal controllersWired and solar controllers with 6, 22, 44 and 56 output options.
- LED traffic signal heads200mm, 300mm and 400mm signal heads with MUTCD, EN12368, GB14886 compliance.
- Signal polesVertical, signal arm and double-arm poles for any intersection geometry.
- Spare parts and accessoriesSpare LED modules, lenses, visors, surge arrestors and anchor bolts.