Bolt head marking

[CdotS]

I have received a couple of bolts with a rather unique markings for failure analysis. It has two lines on its head. There is no such markings in the standards. I attach a photo of one of the bolts. If you know any info on this bolt, please let me know. Thanks.

 

[tfro]

Did you look at a manufacturer's identification table? Here's one, but I didn't see it in there giving it a quick glance over.

http://www.uspto.gov/web/offices/tac/fqa/active.pdf

Here's another larger list, but you have to pay for it:

http://www.indfast.org/book_details.php?prod_num=REF-0001

 

[CdotS]

Yes, I have tried the uspto site but this bolt marking is not listed. I will wait for awhile before paying for the second reference.

 

[rconner]

Not professing any particular expertise here, but I suspect for whatever it is worth this "bolt" (or stud?) "head" may not be a high tensile variety, as I think most common standards require those at least to be recognizably marked.

 

[desertfox]

Hi CdotS

Have a look at this site two lines shown here is an SAE grade 3 medium carbon steel.

http://shopswarf.orconhosting.net.nz/boltid.htm

hope this helps

desertfox

 

[CdotS]

Thank you all for your immediate response.

 

[desertfox]

CdotS

your wecome, is the bolt an SAE grade 3?

desertfox

 

[CdotS]

It could be SAE Grade 3 and I will report here once the chemistry and hardness are done. Not enough material for tensile testing.

 

[desertfox]

okay CdotS

thanks for updating us in advance

desertfox

 

[mizzoueng]

Hey, I know it may be a bolt, but that looks kinda like the DD rivet marking. 2024 aluminum.

http://www.mlevel3.com/BCIT/rivetID.htm

 

[CdotS]

Mizzoueng, believe me, it is a bolt with top view taken just to show the markings. Do not let your imganination run too far.

 

[ornerynorsk]

Looks like it might be a weld projection head, but it doesn't look like a typical example.

 

[rconner]

[Just curious, exactly what kind of "head" is on this "bolt"?]

 

[SincoTC]

If that's a "bolt head", how the heck do you tighten it?

 

[CdotS]

It is a plow bolt. It has a small square section under the head. The part has a square hole with a countersink.

when I post hardness readings, I will include another photo for you. Please bear with the delay.

 

[SincoTC]

So you tighten the nut on the other side, making it more of a headed stud than a bolt really, but I realise they may still call them bolts.

Do you think that maybe the marks are there just so that you can note the orientation of the square in the part, to check that it hasn't started to round out the hole when the nut is tightened and the head may be out of view?

 

[TVP]

SincoTC,

Bolts are not tightened by applying torque to their head-- they are tightened by torquing the nut. Screws are tightened by torquing their head. This is the consensus definition used by IFI, ASME, ASTM, ISO, etc.

 

[SincoTC]

TVP,

You're quite correct, that is the current consensus on the definition of bolts and screws, but nearly everyone in this thread has spoken of "bolt head" including the OP. I suppose in my first post, it would have been more correct to say how do you "stop it turning", but for an old fart like me, with my formative years spent in the "infernal combustion engine" business, a "screw head" will always be something to do with woodworking and there must still be loads of old flat-head engines about with "cylinder head bolts" and millions of "big end bolts" holding con-rods together, all with hex heads, all screwed into tapped holes and then torqued down by the head!

The essential point I was making in my second post is that in the absence of spanner flats or similar and with what appears to be a plain cylindrical head with a hidden way of stopping rotation, you need something (maybe the two marks) as a reference to indicate that it hasn't turned when the nut is tightened. The nut may have seized or run up against the end of the thread if a washer is left off or the part it secures has been machined down in thickness, without a suitable witness mark, all the torque applied to the nut may just be destroying the square under the head or the hole it fits in.

 

[SnTMan]

CdotS, if you're still with us, can you contact your supplier?

Regards,

Mike

 

[CdotS]

I am a bit surprised at the direction this post has taken.
I had only the head portion of a broken bolt and wanted to know what type of bolt that was. I figured out from the standards that was a Grade 3 bolt (thanks to those who helped me).

SnTman,
What kind of info do you want me to get from the bolt supplier? I do not know whether it is possible.