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Hanshin Neji (Thailand) Co.,Ltd.
Supply all kinds of fasteners.

CAUTION! hydrogen brittleness!

Especially ZINC CAP SCREW in Thailand.

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Do you have experience that the High strength bolt has been broken on the head?

There is high possibility about hydrogen brittleness.

“hydrogen brittleness” is phenomenon that the hydrogen gets into the bolts and makes the strength the bolts.

Normally in the process of zinc plating, hydrogen gets into the bolts. If you have baking process let the hydrogen out, it will be no problem. But if the bolt has strength over 10.9 such as 12.9 cap screws, it is very difficult to let them out and the hole of hydrogen will remain inside of the bolts. It caused the bolts might be broken after fastenening.

First of all, please check the bolt in your factory!!!

Please check letters on the head!

10.9 ZINC

No problem

12.9 Black oxide

No problem

12.9 ZINC

NOT OK

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10.9 ZINC CAP SCREW M3-M20, PLENTY OF STOCK

PERFECT Quality and Knowledge

Please trust NEJI SPECIALIST HANSHIN NEJI (THAILAND)!

 

Latest Update 13 Mar 2019
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