Metal finishing Q&As since 1989

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Hot Dipped Gal vs Mechanical Gal

The company I am currently working for has traditionally been of the view to offer the Australian market with hot dipped gal chain. Although we have been looking at mechanical gal pricing to see what level of premium exists for hot dipped gal and whether we should re-consider our position and possibly change over to mechanical gal especially for our smaller sized chains. Given the spiraling cost of steel we want to re-evaluate our future direction - The question we are asking ourselves is should we stay with hot dipped or should we switch to mechanical gal? In your opinion what are the merits for doing this other than price? Can you tell me the advantages/disadvantages in both methods? Would a hot dipped gal chain outlast a mechanical gal chain assuming they had the same coating thickness? Are there any other methods other than hot dipped gal or mechanical gal that may be relevant for use on chains?

Vanessa Gould
Product development - Australia
July 9, 2008

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July 11, 2008

I wonder what you mean by "mechanical galv"?
This term could mean sherardizing, or perhaps the technique of rumbling steel in zinc dust [on eBay or Amazon] then there is no comparison in performance.
Hot dip galv and sherardizing both involve some metallurgical bonding between the zinc and the steel, and its hard to get the two to separate.

But mechanical plating is not metallurgically bonded (no alloy formed) and the coating is liable to chip and crack off.

If the chain is for marine applications, like anchor chain for example, then you might find some resistance to buying it. As a sailor myself, I wouldn't dream of buying mechanically plated anchor chain.

Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK