Help Identifying a bolt

[MattBores]

I have 8 hex head bolts I pulled from a load cell and cannot identify the manufacturer or properties of these bolts. The only information I have is engraved on the head of the bolt is the symbol "I^2" (without the ^ symbol).

Can anyone help point me in the right direction here?

 

[vpl]

You mean it says I²?

Patricia Lougheed

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[MattBores]

Yes,

I cannot find a clue anywhere as to who made this or what it's properties may be.

 

[MattBores]

The only other information I can add is I just tested the hardness, and the bolts are coming out ~45Rc.

Can anyone help suggest what grade this might be?

 

[vpl]

I looked here, but didn't see it. If I have time, I'll do some other searches, but can't promise anything.

Patricia Lougheed

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[CastMetal]

Did the mounting bolts possibly come with the load cell? Contact the load cell manufacturer?

Comprehension is not understanding. Understanding is not wisdom. And it is wisdom that gives us the ability to apply what we know, to our real world situations

 

[MattBores]

Since it has a hardness of 45Rc this equates to a tensile strength of roughly 214,000 PSI, which is higher than a grade 8 bolt to my knowledge. I have no idea what this is

 

[ornerynorsk]

How can you approximate the tensile strength without knowing the material? What alloy are you assuming it is?

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[MattBores]

I used this:

http://www.unified-eng.com/scitech/hardness/hardness.html

to approximate tensile strength, which assumes carbon and alloy steels in the annealed, normalized, and quenched-and-tempered conditions.

 

[ornerynorsk]

Different materials have different tensile values at the SAME hardness.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[Kwan]

I found some info. I looked thru quickly, but I did not see the mark you are looking for.

http://www.dot.il.gov/materials/fasteneridentificationguide.pdf

 

[racookpe1978]

Can you find a 9th bolt?

Then you pull the 9th bolt in half and record the tension. Use that (destroyed) bolt as a material sample, and compare its chemistry to the rest.

 

[berkshire]

Are you sure you are not looking at a 12.9 grade bolt?
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[vpl]

My previous link was to the US DOD Handbook "Listing of Fastener Manuacturer's Identification Symbols" (MIL-HDBK-57E):

http://www.dscp.dla.mil/contract/pdf/MIL-HDBK-57E.pdf

The I² symbol doesn't seem to be in there. The only other reference that I can find that is more of an international one is "The Fastener Manufacturer Identification Symbols International Guide" by Fastener Technology. I don't have a copy of this, so I don't know if the I²

Patricia Lougheed

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[kmenke]

Sorry MattBores, I don't see any I2 in any of the registered fastener manufacturer's markings books that I have. This isn't too uncommon though. Products made per print can be marked with whatever the enduser desires. If the information is available from the load cell manufacturer this would be a good place to start. Otherwise there are some fastener suppliers/manufacturers that can test chemistry and hardness for you.

http://www.fastenal.com/web/services.ex?action=CustManf

Assuming through hardened to 45Rc, this is a relatively high hardness for a threaded fastener. What is the application for these fasteners?