the dimension about galvanizing thread

[wzhang29]

I have a confusion about the dimension about external galvanizing thread. Is it ture that the bolt thread is in standard dimension before galvanizing? Your reply is much appreciated.

 

[CoryPad]

In ISO 7411 Hexagon bolts for high-strength structural bolting with large width across flats (thread lengths according to ISO 888) — Product grade C — Property classes 8.8 and 10.9, it is stated that the thread tolerance is 6g before hot-dip galvanizing. It is also stated that it is allowed (by agreement between purchaser and producer) to produce the threads undersized to class 6az to accomodate the thickness of the hot-dip galvanizing layer.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[wzhang29]

Thank you Cory for your help.