EPIC nuts/studs loosening thread (reposting stupid stuff without reading = warning)
#783
Which Resbond are we talking about here?:
And who's tried loosening them afterwards?
http://www.cotronics.com/vo/cotr/pdf/907ts.pdf
And who's tried loosening them afterwards?
http://www.cotronics.com/vo/cotr/pdf/907ts.pdf
#785
I checked our material tracker, and we carry A286.
The last order that went out was for 3/4" x 4" all thread studs...they sold for $14/pc.
I tried to tell Travis he give us a call and see what Sales and Methods could scrounge up...but he didn't take the advice.
We also do the heat treating.
The last order that went out was for 3/4" x 4" all thread studs...they sold for $14/pc.
I tried to tell Travis he give us a call and see what Sales and Methods could scrounge up...but he didn't take the advice.
We also do the heat treating.
I must of not seen it gospeed. I usually check every tip for price.
A286 1800/1325 is perfect. coefficient of thermal expansion is twice what inconel is, its stronger at temperature, lower creep, the whole bit.
#789
690 and 706 seem to have the highest CTE as per Online Materials Information Resource - MatWeb with more common alloys right at about normal steel.
A286 starts out at low temperatures with 9.39 and goes to 10.8uin/inF* at high temperature (1500+)
Inconel 690 starts out at low temperature with 7.81 and goes to 9.672 at high temperature (1500+)
690 is also about half the yield strength of A286.
706 is even weaker then 690.
What alloy are you using because I'm not seeing it. Thats the best case scenario for your material selection from that database atleast.
I guess I should clarify here. Given A286's superior physical, and CTE properties, it will tolerate twice to three times the total stretch of 690 or 706 in high temperature given an equal preload.
A286 is actually a stainless steel. Grade 660. SO it expands like a stainless steel. It also has the freak property of a very strong stainless steel at high temperature.
A286 starts out at low temperatures with 9.39 and goes to 10.8uin/inF* at high temperature (1500+)
Inconel 690 starts out at low temperature with 7.81 and goes to 9.672 at high temperature (1500+)
690 is also about half the yield strength of A286.
706 is even weaker then 690.
What alloy are you using because I'm not seeing it. Thats the best case scenario for your material selection from that database atleast.
I guess I should clarify here. Given A286's superior physical, and CTE properties, it will tolerate twice to three times the total stretch of 690 or 706 in high temperature given an equal preload.
A286 is actually a stainless steel. Grade 660. SO it expands like a stainless steel. It also has the freak property of a very strong stainless steel at high temperature.
#792
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Sav, what grade of inconel are you going to be testing? What are the specs?
A few I specs I found:
Super Alloy A-286
Mean Coeff Thermal Expansion 9.17
Modulus of Elasticity Tension 29.1
4130 alloy (Stage-8 bolts)
Mean Coeff Thermal Expansion 7
Modulus of Elasticity Tension 29
Super Alloy Inconel 690
Mean Coeff Thermal Expansion 7.8
Modulus of Elasticity Tension 30.6
#793
Inconel 690 is the money.Have any of you used any of these materials?Are any of you material engineers?Have any of you spoken to an airframe mechanic?All of the bolts in a jet engine are Inconel(of various alloys)Have you every machined Monel?Then,you are only quessing.
-G-
-G-
Last edited by Reverend Greg; 09-28-2009 at 09:11 PM.
#795
Former Vendor
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Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,100
I'm not going to say which specific alloy since I don't want to spend $500+ testing this stuff only to have someone find a supplier and go around me.
At 1000F:
Young's modulus ***
CTE ***
Yield strength (.2% offset): ~****
At 1000F:
Young's modulus ***
CTE ***
Yield strength (.2% offset): ~****
Last edited by Savington; 03-30-2018 at 12:34 AM.
#797
Inconel 690 is the money.Have any of you used any of these materials?Are any of you material engineers?Have any of you spoken to an airframe mechanic?All of the bolts in a jet engine are Inconel(of various alloys)Have you every machined Monel?Then,you are only quessing.
-G-
-G-
Not guessing. My money is on Sav (well, if you insist on holding up a turbo AND sealing the flange with only 4 bolts then my money is on Sav).
But since Travis came out with his top secret material selection I decided to check (as it sounded familiar) and sure enough, we've sent out a few orders of it.
When I'm at work Friday I'll look into it a little more. Regardless, we likely don't just have the size and material we need sitting on a shelf...and even if it was I don't do the five-finger discount thing.
They would have to be made...but I'd tell sales they were full of **** if they wanted $25 a piece for 'em.
#798
Inconel 690 is the money.Have any of you used any of these materials?Are any of you material engineers?Have any of you spoken to an airframe mechanic?All of the bolts in a jet engine are Inconel(of various alloys)Have you every machined Monel?Then,you are only quessing.
-G-
-G-
I think anyone with simple math can look at the numbers and tell which material is superior. Simple simple math, but your still voting on 690 just because?
I have already showed via a time transient computational fluid dynamics model simulated differentials in temperature by which should be consistant with what such a translation in throttle would provoke which would invoke plastic deformation of standard materials.
(The temperature difference causes crappy bolts to break)
I have carefully and dynamically matched this material not to any paticular static condition but over a wide range of transients mathematically such that the worse case scenarios present situations which are not possible and such that its coefficient of thermal expansion matches the joints non-uniform temperature distribution against its non-homogenious bi-material make up to deliver the most consistant preload.
(I found a super expandy metal)
After doing so I computed the stress on the material using its thermal strain and have found A286 to successfully take the load under a determined (by me) preload and referenced these stresses to S/N curves and have determined failure in cycles at max S is nearly off the chart at my properietary preload numbers, and that under this preload the joint will hold any turbo you can fit under the hood.
(I made sure it could hold up to track abuse without your turbo hitting the fender well)
I think I done ok on the engineering side of it. How did you determine which material was the best. Pick a tiger by the toe?
#799
Want me to go get a scantron and we can go ahead an go at this like real men. 2 men, 2 pencils, 1 test, who will walk away!!!
I think anyone with simple math can look at the numbers and tell which material is superior. Simple simple math, but your still voting on 690 just because?
I have already showed via a time transient computational fluid dynamics model simulated differentials in temperature by which should be consistant with what such a translation in throttle would provoke which would invoke plastic deformation of standard materials.
(The temperature difference causes crappy bolts to break)
I have carefully and dynamically matched this material not to any paticular static condition but over a wide range of transients mathematically such that the worse case scenarios present situations which are not possible and such that its coefficient of thermal expansion matches the joints non-uniform temperature distribution against its non-homogenious bi-material make up to deliver the most consistant preload.
(I found a super expandy metal)
After doing so I computed the stress on the material using its thermal strain and have found A286 to successfully take the load under a determined (by me) preload and referenced these stresses to S/N curves and have determined failure in cycles at max S is nearly off the chart at my properietary preload numbers, and that under this preload the joint will hold any turbo you can fit under the hood.
(I made sure it could hold up to track abuse without your turbo hitting the fender well)
I think I done ok on the engineering side of it. How did you determine which material was the best. Pick a tiger by the toe?
I think anyone with simple math can look at the numbers and tell which material is superior. Simple simple math, but your still voting on 690 just because?
I have already showed via a time transient computational fluid dynamics model simulated differentials in temperature by which should be consistant with what such a translation in throttle would provoke which would invoke plastic deformation of standard materials.
(The temperature difference causes crappy bolts to break)
I have carefully and dynamically matched this material not to any paticular static condition but over a wide range of transients mathematically such that the worse case scenarios present situations which are not possible and such that its coefficient of thermal expansion matches the joints non-uniform temperature distribution against its non-homogenious bi-material make up to deliver the most consistant preload.
(I found a super expandy metal)
After doing so I computed the stress on the material using its thermal strain and have found A286 to successfully take the load under a determined (by me) preload and referenced these stresses to S/N curves and have determined failure in cycles at max S is nearly off the chart at my properietary preload numbers, and that under this preload the joint will hold any turbo you can fit under the hood.
(I made sure it could hold up to track abuse without your turbo hitting the fender well)
I think I done ok on the engineering side of it. How did you determine which material was the best. Pick a tiger by the toe?