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.
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.
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.
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!
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
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.
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.
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.
