Yield strength conversion to shear strength.
Yield strength conversion to shear strength.
(OP)
Blueprint called out for material corrosion resistant steel A286 per AMS5732with a 95,000 PSI minimum shear strength. The material Cert shows only Yield strength: 121,000 PSI and Tensile strength: 161,000 PSI.
The mill company said AMS 5732 does not call for shear strength. I dont have the spec, and It would take a day to get one. what is the formula to convert Yield strength to Shear strength? or would be better to send the material for shear strength test anyway?
The mill company said AMS 5732 does not call for shear strength. I dont have the spec, and It would take a day to get one. what is the formula to convert Yield strength to Shear strength? or would be better to send the material for shear strength test anyway?





RE: Yield strength conversion to shear strength.
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RE: Yield strength conversion to shear strength.
RE: Yield strength conversion to shear strength.
RE: Yield strength conversion to shear strength.
TVP is right that you can't just do a conversion; you have to actually get test results for shear. Depending on length it might be a double or single shear test. Headed pins are intended for shear loading in service, so that is why you have to get actual shear results to ensure proper HT response.
RE: Yield strength conversion to shear strength.
the pin itself has a strength ... if UTS = 160ksi, USS = 91 ksi (as a rule of thumb, looking at the tables it seems more like 95 ksi)
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RE: Yield strength conversion to shear strength.
RE: Yield strength conversion to shear strength.
if the fasteners are certified to the AMS, then they meet the AMS standard (IMHO).
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RE: Yield strength conversion to shear strength.
RB; all the pins that we have done have a single or double shear test requirement, since that will be the failure mode. AMS is a raw material spec, I can get all sorts of different finished part tensile strengths out of AMS5732. You always have to provide test results to the finished part requirement, in this case they want shear, which is not specified in that document, so he is going to have to go out and have some parts sheared.
On aerospace fasteners, almost every lot of finished parts requires a shear test (except for those parts that are too short, small, big, etc.) since the majority of parts are designed for shear loading and a shear test is an easy way to validate proper heat treat.
RE: Yield strength conversion to shear strength.
RE: Yield strength conversion to shear strength.
but if you are working with other people's parts, then hasn't the other person certified that the part is good ?
if you're working with your own part, then the engineering definition should match the design intent. in this case it sounds like they don't match explicitly; either change the stregth call-out for specify UTS (which defines the heat treat, no?) which is tested by the ASM, or change the ASM to one that tests shear strength.
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RE: Yield strength conversion to shear strength.
thank you guys for your help.
Regards
RE: Yield strength conversion to shear strength.
if it certified, it is good and meets the spec requirements and additional testing to verify properties not expressly tested is, IMHO, unnecessary.
if the UTS is 160 ksi and the spec drawing calls up 95 ksi Fsu, i don't think there's a problem because 0.57*UTS = 91 ksi.
if it's a fake cert, then your testing will reveal it (just as if you repeated the UTS test required by the spec).
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RE: Yield strength conversion to shear strength.
RE: Yield strength conversion to shear strength.
maybe it's another command, but for where i am you're all tarred with the same brush (and that's NOT a racial slur).
maybe it's a tonne of paperwork to get another command interested in this, maybe this is just a windmill (to tilt at).
but if you're interpreting the certificates as saying "i've checked UTS" and not as "i've complied with the spec",
and so continue "i need to verify Fsu" and not "Fsu is defined by having on-spec material"
because you see a disconnect between what's specified (Fsu min) and what's tested by spec (UTS)
then IMHO it makes sense to either ask NASC is the certificate accept for demonstrating on-spec material (and so meeting the Fsu required),
or tell NASC the spec choosen doesn't test the key engineering feature (Fsu) so change the spec to one that does (ie align the test with the spec);
clear as mud ?
but as i've opinioned, several times, i think your material meets the spec requirements and i'd be surprised if someone backs you up, supports either your requ for further testing or your request for drwg change.
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RE: Yield strength conversion to shear strength.
Doug
RE: Yield strength conversion to shear strength.
It is very common for the part print to have additional requirements beyond what is included in the AMS spec. AMS speaks to material, and the part print speaks to functionality. A good example would be NAS1580 for the part print, which has the Fsu on it for the various materials (alloy, Cres, Ti),then the required testing is covered under the procurement spec: NAS 4003, 4004 etc. The required AMS materials listed on NAS1580 do not make reference to Fsu in the finished part, since at the material level it is unknown which particular HT spec will be applied to the material.
I don't understand why you want Fran to try to get a change; this is the normal practice for fasteners. We deal with it all the time, you certify the material to the requirements of AMS and then after fabrication you test finished parts to the part print requirements, which can be in addition to requirements listed in AMS.
RE: Yield strength conversion to shear strength.
but i notice that AMS5737 has Fsu = 95ksi ... typo ?
it sounds like there's an engineering problem between the drawing call-out (95 ksi min) and the process spec ? (I had assumed that they were compatable)
now for this detail part, additional testing will probably clear the drawing requirement (which doesn't look to be met by the process spec)
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RE: Yield strength conversion to shear strength.
Doug
RE: Yield strength conversion to shear strength.
@jagad5, Im thinking the same. I dont think this material will pass the shear test, will wait until the results from the Lab come back.
@rb1957, this is a CSI fastener, I can't place an EO for this shear strength requirement.
RE: Yield strength conversion to shear strength.
When I look around on this topic here’s what I come up with: The yield stress in shear is approx. its theoretical value of Fy/[sq.rt.(3)] = .58Fy or .58 times the yield strength in tension, this comes from the Hencky-von Mises yield criteria; and tests usually indicate the ultimate shear strength ranges from 2/3 to 3/4 of the ultimate tensile strength. When you order the material find out what the mill or supplier provides in the way of testing with its mill certs. Many times you can negotiate with them and get them to include other tests on the certs., for some extra cost, of course.
RE: Yield strength conversion to shear strength.
on-spec material doesn't meet the drwg reqmt, so you need to do the additional test. given that FTU is 160ksi (spec = 130ksi), i'd expect that you'll get your 95 ksi Fsu.
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