Stretched A1 rod bolts !!!

[JOHNBOY]

I don't believe that there is a lot of people who are mesuring their brand new fasteners when they put them in ! Are you ?

Yes I am. And I always do. You should to. These are not Legos do build them like they are. You should measure every bolt. Keep the measurements in a note book. You should make sure you know which bolt went to which rod and which side. Just like you should know what clearences you have on you bearings, How thick your bearings are at the crown, piston to wall clearence, piston protrusion, and so on. If you think the top engine builders just grab a torque wrench and go to town you have much to learn. Mocking up and tearing down an engine 3 to 5 times to check things is not uncommon before the final build.

The fact that you dont know how long your bolts are is your fault. You should be responsible for replacing the bolts on your own dime as you can not prove that the bolt was not that way when you got it.

I looked at my notes and I see that out of the box the length varies .018 for my bolts. They will not all be the same length. The treads are not cut they are rolled. A process where an already hardened blank is put between to larger rollers. The roller spin as the press together forming the threads on the blank. If the blank is a little bigger than the rest the extra materail is forced to the end making the the part longer. A difference of only .001 can make a suprising difference in the length of the formed part. I know this because where I work we have a thread roller.

 

[Joesixpack]

The fact that you dont know how long your bolts are is your fault. You should be responsible for replacing the bolts on your own dime as you can not prove that the bolt was not that way when you got it.

What the hell does he have to prove, the bolt won't hold 90lbs torque and you can even visually see the threads longer and narrowed out from stretching in the photo?????????

It's a dud. Didn't temper....who knows, but needs replacement thats for sure.

 

[Ragged Edge]

What the hell does he have to prove, the bolt won't hold 90lbs torque and you can even visually see the threads longer and narrowed out from stretching in the photo?????????

It's a dud. Didn't temper....who knows, but needs replacement thats for sure.

I say he didn't torque it correctly, I done it before myself

 

[blacksmoke83]

I say he didn't torque it correctly, I done it before myself

OK, listen that !

At work, I'm the guy who rebuild our jet engines, those are ROLLS-ROYCE AVON 207 series jet engines. Believe me, in those engines, everything is about torque loads and clearences. In aviation world, there is no place for mistake, if something goes wrong, the bird goes down. In 5 years, I never had any problem with the engines that I had rebuild.

All our torque wrench are tested and calibrated twice a year, It's the law !

I had used a ½ drive SNAP-ON load cell torque wrench to torque those bolts and I was not able to reach 90FT LB on 1 bolt out of 12

Torque spec for those bolts are 30FT LB - 45FT LB and 90FT LB, retorque to 90FT LB

So, did I torque it correctly ?

 

[Tate]

OK, listen that !

At work, I'm the guy who rebuild our jet engines, those are ROLLS-ROYCE AVON 207 series jet engines. Believe me, in those engines, everything is about torque loads and clearences. In aviation world, there is no place for mistake, if something goes wrong, the bird goes down. In 5 years, I never had any problem with the engines that I had rebuild.

Working on turbines, I would have expected you to know that you do a prestretch measure and a post stretch measure. I haven't had to measure any stretch on any of my fasteners in my engine. At work, on the other hand, any fastener we stretch, we measure. And that is over a hundred studs depending on the machine, usually well over 2' long, some up to 5'.

 

[JOHNBOY]

What the hell does he have to prove, the bolt won't hold 90lbs torque and you can even visually see the threads longer and narrowed out from stretching in the photo?????????

It's a dud. Didn't temper....who knows, but needs replacement thats for sure.

He did not pe measure the bolt. he stoped torueing it because the length he measured was long. Why it was long he does not know. Not measuring was his fault. That toque number is an upper limit. You torque the bolt checking to get the correct stretch with out exceeding that number. If you can not get the stretch by 90 something is wrong, Tear it down try again.

I say he didn't torque it correctly, I done it before myself

Bingo

OK, listen that !

At work, I'm the guy who rebuild our jet engines, those are ROLLS-ROYCE AVON 207 series jet engines. Believe me, in those engines, everything is about torque loads and clearences. In aviation world, there is no place for mistake, if something goes wrong, the bird goes down. In 5 years, I never had any problem with the engines that I had rebuild.

All our torque wrench are tested and calibrated twice a year, It's the law !

I had used a ½ drive SNAP-ON load cell torque wrench to torque those bolts and I was not able to reach 90FT LB on 1 bolt out of 12

Torque spec for those bolts are 30FT LB - 45FT LB and 90FT LB, retorque to 90FT LB

So, did I torque it correctly ?

Good for you. If you work on Rolls engines you probably install parts we make. You should know that there is a torque limit and a a stretch tolerance for the fastener. It is more important by far that you get the correct stetch then it is to get to the max torque. Something an AV Tech like you should know.wned:

Buy another set. Mooching free ones just drives up the costs for the rest of us. Or at least send the fasteners back to A1 to be examined and let them make the call.
If you call the company I work for and said this fastner failed and that you did not premeasure and monitor stretch we would tell fine. We have no issues selling another. But I can assure there would be no hands outs.

Working on turbines, I would have expected you to know that you do a prestretch measure and a post stretch measure. I haven't had to measure any stretch on any of my fasteners in my engine. At work, on the other hand, any fastener we stretch, we measure. And that is over a hundred studs depending on the machine, usually well over 2' long, some up to 5'.

:thankyou2: