Hot dip galvanized steel

[sowhatso]

Contractor delivered to the job site structural steel which was specified as hot dip galvanize. I have a feeling the steel was just painted with silver paint or it may be cold galvanize.

Is there a simple field test that I could do in the field to verify the steel was hot dip galvanized and not just painted or cold galvanize?

Thanks for your input

 

[JLSeagull]

Ask the supplier if they can provide a test specimen from that batch. ASTM A 123 mentions Test Method B 602 and includes a few paragraphs related to testing the coating thickness, magnetic thickness, microscopy, etc. ASTM A 653 references Test Method A 90. If you have to chip of the actual material, ASTM A 780 pertains to repair of damaged and uncoated areas.

 

[JLSeagull]

Testing methods can be found in ASTM E 376 and A 239.

 

[rcooper]

Freshly galvanized steel is bright and shiny. It dulls over a short space of time (a week) to give the normal dull grey appearance.

 

[100320]

I have a problem with mechanical test hotdip for bolt & nut, when bolt [in] drawing will be happened ductile at nut which resulted from by oversize, because the standart astm e.g A325 just tell minimal value don't explain that black or hotdip. so how to explain to customer [of] about this
sometime cutomer/client do not want to know about this.
Thanks for your input

 

[me1abpsu]

You can easily tell if something is hot dipped versus cold galvanized. Like Rcooper said, the hot dipped steel will be very shiny, and cold galv will be dull looking.

Now to determine if it was painted. Can you risk taking a wire brush grinder to the steel? If so, paint should come off with no hassle, but H.D.G. will take some effort.

If you can't take that risk, just look at it to see if you can see grain boundaries in the steel. This isn't a guarantee, but if you do it's most likely H.D.G.

Regards