Metric nut yield strengths 1

[Philrock]

Where can I find the yield strengths of metric class 4, 6, 8, and 10 nuts? I have been able to find proof strengths and hardness, but not yield strengths.

 

[dimjim]

I will check with MarylandMetrics and see if anything
is on that website. Good question.

 

[dimjim]

http://www.marylandmetrics.com/fastindx/t18u.pdf

Does this help?

 

[Philrock]

Dimjim,

Thanks for the lead - I had seen this before - it gives proof strengths and hardness, but not yield strengths. I'm writing software to calculate thread stripping loads / safety factors (among other things), so I need yield strengths.

 

[desertfox]

Hi Philrock

Any material that dosen't have a marked or sudden yield point are given proof stress values.
So the values you are seeing are the nominal stress to create a specified amount of plastic strain the usual values are quoted the produce 0.1%,0.2%,0.5%.
I would use these values with a good safety margin to use for your spreadsheet design.

regards

desertfox

 

[unclesyd]

Have you looked at this article

http://www..hexagon.de/dose/dose-1e.pdf

 

[dimjim]

Ok!
From PSL Catalogue Page 19
Classification of Bolt Yield Point (MPa) Rp0.2
8.8 10.9 12.9

640 940 1100

I would hope that the nuts would have to be
at least this high. I will keep checking
other resources.

The values that Shigley shows in his book again
is only for the bolts, rivets, sems, etc. and
is as you probably know is that the whole number
represents the utimate tensile x 100
where the decimal is the approximate ratio of
the yield strength to the tensile.

The PSL catalogue shows that the testing strenght
of the nuts must be equivalent to the Tensile
Strength of the Bolts so that is no help either.

Will keep looking. Shigley at least shows the
yield strength for all of the metric grades of
bolts. I am starting to see your dilemna.
Will keep looking!

 

[desertfox]

Hi All

Unclesyd I can't get your link to work.

dimjim your yield stress quoted in your last thread is a proof stress to produce a plastic strain of 0.2% ie:- Rp0.2.
Have a look at this definition of proof stress at this site:-
regards

http://www.matter.org.uk/glossary/detail.asp?dbid=606

desertfox

 

[unclesyd]

On the url below click on the "Bolted Joint Design" and hit end to look at bottom of the page then checkout:
"Thread Strip Safety according to Dose"

http://www.hexagon.de/

 

[Philrock]

unclesyd,

Dose's paper is excellent. Thanks for the lead.

 

[desertfox]

Hi unclesyd

Good link very informative.

Philrock please note that only proof stresses are given for the bolt materials in unclesyds link not yield stress, however the ultimate tensile strengths are given too.

regards

desertfox

 

[dimjim]

This article too only gives proof loads.

http://gltrs.grc.nasa.gov/reports/1990/RP-1228.pdf

 

[unclesyd]

You might want to checkout the tools to perform the proof tests on nut/bolts at this site. Using their equipment and software can get all the physical properties of a fastener system.

Instron did have a bunch of information on the testing of fasteners but I've not been able to relocate it.

Click on "More about this category..." at the top of the page.

http://www.instron.us/wa/acc_catalo...ing+Assembly+for+Fastener+Holders&ref=http://

http://www.google.com/search

 

[vonlueke]

Philrock: ISO 898-2 doesn't list nut yield strength. A nut of property class n can support greater than or equal to the bolt proof strength load of a property class n.j bolt without encountering permanent deformation of the fasteners (meaning the nut is removable by the fingers after the load is released). You can estimate the nut yield strength as equal to the corresponding bolt property class yield strength.

You should specify a nut such that the nut property class matches the bolt property class number preceding the decimal point. I.e., a property class 5 nut goes with a property class 5.8 bolt, a property class 10 nut goes with a property class 10.9 bolt, and so on.