Grade 8 Bolt Marking Symbol
Grade 8 Bolt Marking Symbol
(OP)
I have a bolt that is now damaged and needs replacement. The bolt has the normal 6 lines indicating it is a SAE Grade 8 bolt, but also has a small triangle between two of the lines. I don't recognize this marking and can't find any references stating its meaning. What does this triangle mean?
It's a 5/8-11 x 3" partially threaded, if that matters.
It's a 5/8-11 x 3" partially threaded, if that matters.





RE: Grade 8 Bolt Marking Symbol
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RE: Grade 8 Bolt Marking Symbol
http://www.infasco.com/infasco/English/index.html
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Grade 8 Bolt Marking Symbol
Do you mind telling me how you found that, or were you familar with the brand?
RE: Grade 8 Bolt Marking Symbol
http
If you really need to know the manufacturer by the head bolt marking, you can purchase a book from the Industrial Fasteners Organization that has many manufacturers (over 1000 I think) and their head markings at:
http://w
Reidh
RE: Grade 8 Bolt Marking Symbol
Hi, does it matter? A grade 8 is a grade 8. The symbol is for ISO tracking. All American and/or World follow the specs. for manufacturing of bolt, nuts and washers. (hopefully).
Cheers
Robert
Could be worse, could be me!
RE: Grade 8 Bolt Marking Symbol
TTFN
Eng-Tips Policies FAQ731-376
RE: Grade 8 Bolt Marking Symbol
No, it doesn't matter at all since it's only a manufacturing identifier (but I didn't know that, so that's why I started the thread). I work on products that don't require graded bolts, so I've never run across this before.
I was assuming that any grade 8 bolt would be fine, but since I wasn't sure I figured I'd ask and see if I could learn something (which I did).
-Thomas
RE: Grade 8 Bolt Marking Symbol
RE: Grade 8 Bolt Marking Symbol
Zuccus
RE: Grade 8 Bolt Marking Symbol
It DOES matter. If you think for a minute that the quality controls are the same between all manufacturer's, you are crazy. We have had problems before in which we were using a grade 8.8 or 12.9 bolt and it was failing. Independent lab tests proved that the bolt was not manufactured to the standard, which was the reason for failure. These were not counterfeit bolts either, they were traced directly to the manufacturer.
In case anybody was wondering, the head marking was "WT".
Reidh
RE: Grade 8 Bolt Marking Symbol
-Thomas
RE: Grade 8 Bolt Marking Symbol
I imagine my above comment may open a can of worms on this forum.
Reidh