ever see a bolt fail like this 4

[djhurayt]

 

[djhurayt]

I'm guessing that there must have been a fold in the raw material prior to the cold heading. ???

 

[EdStainless]

A joint in the rod?
Thy don't look like they were attached, just against each other.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[djhurayt]

This was an installed bolt. I went to remove it this weekend and thought oops my wrench slipped, looked down and holy cow it wasn't the wrench the whole head slipped off the bolt.

 

[metengr]

Based on the appearance, it appears like a rather large, inclusion or lamination type defect was present in the original bar material.

 

[Compositepro]

I've never seen anything like it, but the failure does appear to to be where the the highest internal stresses would be expected from quenching. I would expect to see evidence of an inclusion, and I don't see any. Perhaps this bolt missed the heat treatment after forming.

 

[tbuelna]

I've never seen this type of failure. But I'm sure if you submit the failed bolt to the metallurgical analysis dept at the neighborhood hardware store you purchased it from, they will recommend a free replacement or a full refund of the $0.39 purchase price.

I'm actually surprised that these quality issues aren't more common with commercial grade zinc plated steel bolts. Making a bolt for just a few cents each is not as easy as it seems.

 

[OSIRIS7]

Looks like there has been a laminar dislocation which grew by bolt tension to the diameter of the bolt hole and clearly stopped there where tension in the material becomes pressure. Then you put torque on it to loosen up, and it is a well known fact that if you want to destroy anything, put torional stress to it. So it came off. It is a very rare thing. I have not seen this before. Probably (and hopefully) never will again.

 

[djhurayt]

Hey I paid $0.42 for that bolt, thank you very much. ha ha
And won't they be surprised when they get the $500 metallurgist bill.

In all reality this was on a motorcycle lift, I do believe I will be replacing all the bolts involved with the lift mechanism before another bike goes up in the air.

 

[ornerynorsk]

Yes, we had this happen on caster studs a number of years ago. The wire feedstock was being cold-headed oversize and the hex sheared/trimmed to size before heat treat. Lateral flow lines of the material in the head were being sheared through, allowing separation after a shoddy job of heat treating. Very odd failure. Once we convinced the shop that the cold heading could be achieved to net shape and dimension without shearing the hex afterward, the problem went away. They would not share the metallurgical report with us, which neatly translated as egg on face.

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.

 

[swall]

It is a heading flaw. Potential causes would be improper material hardness, improper microstructure, improper lube on the wire rod. if this is a one of a kind, you can probably rule out a die design issue.

 

[racookpe1978]

What? You didn't want one of those new thin-headed bolts? They save weight and material!

An MIS-TAKE (er, MIL-SPEC) aeor-assembly (er, aerospace (er, error-space) assembly) using those style thin-headed costs $3500.00 per head. One-time use guarraneeted! (you can always put it together, you just can't use much torque keeping it together.)

 

[djhurayt]

Let me clarify that this was a bolt on a motorcycle lift at home. And I am not really looking for root cause because we are seeing issues, although I was interested to see what others thought. Was more or less just posting it because it was so unusual (to me anyhow). And fortunately this was not under a lot of torque and was mainly a shear mode usage. But you can bet that any bolts on this that are in tension will be replaced.

 

[moltenmetal]

That's a freaky failure. Never seen one like it, and hope to never see another! Hope it's not a sign of things to come...

 

[SnTMan]

Motorcycle lift? Home? Harbor Freight perhaps?

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[djhurayt]

yes HF, and yes there is my answer to the quality of the hardware provided

 

[btrueblood]

You can see the shear lines where the head was trimmed, as per ornery's post. Replace it with bolts that have no evidence of such trimming on the hex faces.

 

[tc002]

Where is the original source of the bolt, Is it known?

 

[dgallup]

It's above, Harbor Freight straight off the slow boat from ... our favorite low cost opportunity country.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[tc002]

I have been following imports of steel products for years, since our steel production of fasteners went from 95%-"made in the USA" to 0%. Many moons ago, circa 1970's, I think if I can remember back that far. I remember writing a letter to some people in Congress after a small investigation and found that the U.S. State dept made a deal with countries in Eastern Europe to assist them in selling their products by exporting them to the U.S. through an importer in Chicago and within 1 year they took over the entire fastener business by cutting prices with subsidies from theitr own government and some grants from our State /dept. I also shipped a nail that I had used on a small home project that was galvanized and it split down the middle into four pieces, looking like a child's toy. I had tested a few more before I took the box back to the hardware store and asked them to put it where the sun didn't shine. They immediately cancelled all orders all orders from that distributor.
From then on, we have gone from producing 125 million tons per year of hot metal steel, now down to about 60 to 70 million tons, the makeup coming from all the third world nations that can produce steel and Chine. Some of our imports come from Europe but now only alloyed and special steels. All the stuff from third world nations and China are suspect of quality and meeting all specs that we publish, all through the U.S. Depts of State and Commerce. I don't know of any imports that are tested, checked analysed for quality today.
The main cause of all this is the WTO, as the politicians have agreed to quantity and a splash of quality but there are no requirements of meeting U.S. Standards that I am aware of. If a country states that the type of steel is-as listed it is checked for tarriffs only. Like food imported the FDA has just so many people and no budget for poisons. For steel products there is no FDSteel and they could care less since by the time the junk rusts out or in this case is found out to fall apart that politician is long gone and on full retirement. One of the great cases in point is the new Bay Bridge in Oakland with the embedded long bolts that have all failed that hold the key to the cables. A 6 billion dollar error that they have tried to cover up since the first failure. Made by a company from Brazil and put into the manufactured piece by the Chinese. This piece is the key to safety of the bridge and we (the politicians) gave the job to outside/offshore outsourcing countries that we consider third world developing nations.
The main cause as indicated is outsourcing, but, when we allow our beancounters to make a selection on price and for profit without any control over quality and how the product is made, I feel we must at least investigate the processing and quality we ourselves adhear to. In your case, you are lucky the motorcycle didn't fall on you as a result of inadequate manufacturing. A law suit over a simple bolt could have changed our imports practice, perhaps and if you had the money for the lawyers. (sometimes they are in good stead. Perhaps some day our professional organizations will take on these issues. Today mostly, we have become pansies.