HDG vs. Galvanized
In fastener specifications you will often see both HDG and galvanized. HDG stands for hot dip galvanized, which is a specific process with defined coating thickness and performance. The word galvanized by itself is more general and can refer to any zinc based coating, including electroplated zinc, mechanical galvanizing, or hot dip galvanizing. Knowing the difference helps you choose the right level of corrosion protection for your project.
What Is HDG?
HDG or hot dip galvanized fasteners are dipped into molten zinc to create a relatively thick, robust coating. This process is often specified for structural steel, outdoor connections, and applications that see frequent moisture or deicing salts. For a concise overview, see our glossary entry on Hot Dip Galvanizing.
What Does “Galvanized” Mean?
Galvanized is a broader term that simply means the fastener has a zinc based protective coating. Depending on the product, this may be:
- Hot dip galvanized
- Electroplated zinc
- Mechanically galvanized or zinc flake type coatings
Because the word is used broadly, it is important to check the product data or spec sheet to confirm whether a part is truly hot dip galvanized, zinc plated, or another zinc system.
When To Specify HDG vs General Galvanized
- Use HDG when drawings, codes, or design requirements call for hot dip galvanized hardware, especially on structural and outdoor steelwork.
- Use general galvanized or zinc plated fasteners when light to moderate corrosion resistance is acceptable and HDG is not required.
Springs Fastener supplies zinc coated and hot dip galvanized options across many product families, including bolts, nuts, washers, and anchors. For help confirming the exact coating on a part or selecting the right finish for your environment, send your requirements through our Request for Quote form or reach out via our Contact Us page.