problem quickly biting

[MassiVonWeizen]

but really to decide what screw you have to use you have to do these calculations instead of using logic and the common sense of putting the screw to wire plate?
But then, if someone has managed to get back the accounts talk to you and confront you, teach yourselves also among you... and what a fool!!! or are you like in elementary school with the handle on the sheet so you don't copy the tabs?

 

[radio]

...
the second piece of the screw (the one that crosses the bottom bracket) must be decomposed into three parts to get the length and you should do so:
point 1)It adds once the diameter then 6mm
point 2)3 times the value of the step that according to table is 0.75
point 3) add a y value which is tabled
...

Be careful because I think you write screws but you mean threaded hole.
the calculations you are describing are most likely those related to a blind threaded hole, in your case we have to deal with a threaded hole that as such does not require a depth of drilling.
v. pdf attached.View attachment FFil.pdf

 

[meccanicamg]

Of course it is the hole and not the vine....bah... these schools do not teach the difference... .

 

[MassiVonWeizen]

Supposing that it is actually the hole that we talk about and not the vine (oh my god:frown the reasoning made by leosci is theoretically correct.
but in the manual hoepli there is a page dedicated to the blind holes that brings depth for deep, normal or short holes.
the first for thread cases with single tool
second in most cases
the third in case thin thicknesses arise (it is here the definition I would say that arbitrary)
I carry an image of the pages (consultable by internet comunque)where you read that the avant-garde is 14mm (11mm if you consider the central column). in both cases you have a sinking of the wall so a blind hole can not be made even because there is no reason to do so.
It should also be considered that these tables were made at the time when the tools were generally in hss, with non-high performing geometries and cutting speeds that tended to make the evacuation of the chip difficult and therefore to demand a greater distance between the useful length of the thread and fine hole. Now with more performing tools that break the chip better according to material, speed and geometry these tables are pure style exercise. I attach a nice pdf View attachment la filettatura perfetta.pdf

 

[MassiVonWeizen]

Here's a nice little page, which saves me too, to bang in the face of the prophecyhttp://www.valvias.com/miscellanea-metric-thread-din-13.php?m=7

 

[leosci]

You guys are wonderful! You don't even need to talk in this forum. I don't even know where to start with all this material you sent me!!!! Now I try to clarify some ideas because it seems to me to understand that I am having the ideas a little too confused. University is worse than elementary school. teachers themselves are very jealous of knowledge.. It is absolutely not my case as my teacher is a very good and very helpful person but often happens to find subjects of this type. anyway digression aside thanks really to everyone. the level of the forum is very high and at the moment I can only draw from you but I hope shortly to be able to give a hand too. :biggrin:

 

[meccanicamg]

qui al post 12 http://www.cad3d.it/forum1/threads/25295-tenuta-filetto?p=209070&viewfull=1#post209070 there is a beautiful demonstration resumed several times because it is good that we understand that the depth of thread from standard, however withdrawn, is not valid.
all depends on the value of the yielding load between lives and mothers.
to keep in mind that there is on the forum and network, an even more theoretical and conservative demonstration (so too from perfect laboratory) that indicates even less thread length.
therefore this demonstration that has been assimilated for tens of years, it does it as a master when you really want to dimensional the extreme threads.

I remember that the value of k if less than 1 is to be reversed numberer with denominator.

 

[MassiVonWeizen]

always from the above mentioned discussion by mechanicsmg regarding its calculation scheme, at post #10, there is a link that should lead to a page with calculation tools. as the page is nonexistent I recovered what I think was the linked page that has this new address http://www.bossard.com/it/engineering/fastener-expert-tools.aspx.
Several tools are inhibited that I suppose will become accessible once registered.