Broken ARP bolt

[MrBo]

Could you post closeup pictures of both fractured faces?

X1000...And, If your going to start a thread like this, you should post up some good friggen pictures.

Put some glasses on and don't be an idiot. Capsure the pic and enlarge it yourself.

The customer has the hardware.

Well, since it’s your thread and not your customers, and since you seem to be claiming it is a defective part and not improper installation and or improper lube, I would expect you to enlarge the picture and post it up.

[rob vine]

maybe you got the one bolt that they pulled and checked off the production line , it was already past its prime when you got it , better odds at winning the lottery , one in a million ,, lmao rob

[CNC BLOCKS]

Well, since it’s your thread and not your customers, and since you seem to be claiming it is a defective part and not improper installation and or improper lube, I would expect you to enlarge the picture and post it up.

Your such a KNOW-ALL-IJEST why don't you enlarge the picture and post it. The customer bought the hardware and he has it not me.

[ZEOHSIX]

Nice attitude "no big thing happens every once in a while" WTF? Why should we buy your product then? Smokey and Carrol Smith are SPINNING in their respective resting places......

[colebalster]

I am a Manufacturing Engineer in the Aerospace Fastener industry. I can tell you that a common failure mode of a bolt loaded in tension will be the head breaking off. To combat this, the head to shank fillet radius is cold worked or "fillet rolled" with a set of circular dies putting compressive force on the radius area to compact the material. This greatly increases the strength of the head. My guess is there was an issue with the fillet roll, raw material, forging process or heat treatment.

To check the fillet rolling process, view another bolt in a copmarator at 25X power and measure the depression of the fillet radius compared to the shank or head underside. There should be at least a .002 depth to the fillet roll.

To check the raw material, you would need to have it examined by a competent metallurgist and investigate the crak formation, beech marks, carburization, etc.

To check the forging process, you must section the part and mount it into an acryllic base (like a hockey puck) and then etch and polish the surface to be able to view the actual grain structure under 100X minimum magnification.

The easiest way to check the material strength is to perform a Rockwell hardness test on the bolt to see where it is? If you can, then it should be at least 40 HRC minimum for 8740 alloy steel (High-Performance Series) and 40 HRC minimum for A286 (Pro-Series). If it is below that value, then the material did not respond to the heat treatment process, or the wrong temperature was used.


When making large batches of fasteners, "shit happens". It's plain and simple. But throughout the process, statistical samples are taken and tested to ensure the whole lot is acceptable based on defined criteria.

Cole

[T-flow]

As much as we have to use and suport them as the "Leader" in the fastener industry. You would think they would atleast treat you nicley... I have called them several times and they have never wanted to talk to me at the same level. Alway's questioning anything in asked or the way it was used or put together.
Never their fault!

I had a bad head stud one time, had a weired spot going down the theads. I called to tell them and ask if they could send me a new one(1 stud). He said " O' you must of crossed threaded it or something". I said, "No, I cleaned it and saw the weired spot in the threads and tried to put the nut on it and it wouldn't go on by head". So I called you.

I had to buy one(1) stud....

[MrBo]

Well, since it’s your thread and not your customers, and since you seem to be claiming it is a defective part and not improper installation and or improper lube, I would expect you to enlarge the picture and post it up.

Your such a KNOW-ALL-IJEST why don't you enlarge the picture and post it. The customer bought the hardware and he has it not me.

I don’t think I can fix your pic Carl.

I have my 400 block engine apart right now. It’s a World block and came with ARP main bolts. For reasons I don’t KNOW, the bolts don’t use washers.
I do know how sharp the edge is on the wrong size of the ARP washer is though, as I have ARP head bolts with washers....
Why are my main bolts used without washers?

[flyingwedge]

Um....because it's a washer faced bolt, an it doan't need one ?

[hodge]

I think it would be better to just use threaded rod instead of special bolts it's cheaper IMOA LOL

[induction apprentice]

I am a Manufacturing Engineer in the Aerospace Fastener industry. I can tell you that a common failure mode of a bolt loaded in tension will be the head breaking off. To combat this, the head to shank fillet radius is cold worked or "fillet rolled" with a set of circular dies putting compressive force on the radius area to compact the material. This greatly increases the strength of the head. My guess is there was an issue with the fillet roll, raw material, forging process or heat treatment.

To check the fillet rolling process, view another bolt in a copmarator at 25X power and measure the depression of the fillet radius compared to the shank or head underside. There should be at least a .002 depth to the fillet roll.

To check the raw material, you would need to have it examined by a competent metallurgist and investigate the crak formation, beech marks, carburization, etc.

To check the forging process, you must section the part and mount it into an acryllic base (like a hockey puck) and then etch and polish the surface to be able to view the actual grain structure under 100X minimum magnification.

The easiest way to check the material strength is to perform a Rockwell hardness test on the bolt to see where it is? If you can, then it should be at least 40 HRC minimum for 8740 alloy steel (High-Performance Series) and 40 HRC minimum for A286 (Pro-Series). If it is below that value, then the material did not respond to the heat treatment process, or the wrong temperature was used.


When making large batches of fasteners, "shit happens". It's plain and simple. But throughout the process, statistical samples are taken and tested to ensure the whole lot is acceptable based on defined criteria.

Cole

Interesting post.

[CNC BLOCKS]

Well, since it’s your thread and not your customers, and since you seem to be claiming it is a defective part and not improper installation and or improper lube, I would expect you to enlarge the picture and post it up.

Your such a KNOW-ALL-IJEST why don't you enlarge the picture and post it. The customer bought the hardware and he has it not me.

I don’t think I can fix your pic Carl.

I have my 400 block engine apart right now. It’s a World block and came with ARP main bolts. For reasons I don’t KNOW, the bolts don’t use washers.
I do know how sharp the edge is on the wrong size of the ARP washer is though, as I have ARP head bolts with washers....
Why are my main bolts used without washers?

No washers kind of looks dangerous and I would think you would get a better torque with washers, Unless the bolts were to short for the application would be my guess.

[af2]

Your such a KNOW-ALL-IJEST why don't you enlarge the picture and post it. The customer bought the hardware and he has it not me.

I don’t think I can fix your pic Carl.

I have my 400 block engine apart right now. It’s a World block and came with ARP main bolts. For reasons I don’t KNOW, the bolts don’t use washers.
I do know how sharp the edge is on the wrong size of the ARP washer is though, as I have ARP head bolts with washers....
Why are my main bolts used without washers?[/quote]

No washers kind of looks dangerous and I would think you would get a better torque with washers, Unless the bolts were to short for the application would be my guess.[/quote]

Maybe the caps are chamfered???

[CNC BLOCKS]

I would think the torque value would change as the washer is harder then the caps.

[ICEMAN]

For a component to fail that quickly, look towards it being a manufacturing defect. One thing you can check, on your end, is parallelism between cap registers and cap boss face; see if the bolt was shear loaded. Picture is blurry, but it looks like a discoloration at the head-to-shank radius. could be a forming lap or quench crack. If it's discolored, that would suggest it was "open" at high temperature.

[gmrocket]

Seriously... you sure you didn't put that washer on wrong.

only one way to tell is to look at the washer to see which side has the blacking scraped/marked up from the bolt. if it was lubed correctly,,a lite coat of the assembly lube on top chamfer face side of washer& or under bolt head and washer dry against the cap....the washer will not turn when torqued. even if you slap lube all over both sides of the washer,,,it should not turn with the bolt when torqued.

so the washer will tell the truth if it was upside down or not.....oh god, what am i thinking ,,this is Carl we're talking about....he probably told all this to the ARP guy when he asked if the washer was installed upside down.