Why not reference the Machineries Handbook? https://www.google.com/search?q=diyhpl.us+%E2%80%BA+papers2+%E2%80%BA+27_Thread_09A&oq=diyhpl.us+%E2%80%BA+papers2+%E2%80%BA+27_Thread_09A&aqs=chrome..69i57.1787j0j4&client=ms-android-att-us&sourceid=chrome-mobile&ie=UTF-8 On Jan 25, 2016 4:33 PM, "Peter Blodow" <p.blo...@dreki.de> wrote:
> Erik, > right tomorrow morning I'll copy another table (fine threads) for you, > for today I have had sufficient wine for not attempting (I found a 30 > year old bottle this afternoon in our rarely used basement room). > > In case you need the size still tonight: the formula: diameter minus > pitch is always correct for metric threads, also for fine threads as M12 > x 1,5, as long as they are 60 degree, als Andy stated. I admit that they > get easier to cut and breakage is less likely as the prefabricated bore > is larger, with the limitation of bore diameter equal to outer thread > diameter. > > Good night > Peter > > Am 25.01.2016 16:07, schrieb Erik Christiansen: > > On 25.01.16 14:28, Peter Blodow wrote: > >> I have run a machine shop with up to twenty workers for 36 years and I > >> never heard about percentage of engagement etc. > > Peter, > > > > On the 10.2mm hole for M12x1.75, given in the table you posted > > yesterday, engagement is 84% - very strong, but hard on taps. > > > > Industry standards are necessary, and we rely on bought bolts > > conforming to them when we tweak % engagement in the tapped hole to > > receive them. > > > > Please have a look at: https://en.wikipedia.org/wiki/Screw_thread > > under the heading "Thread depth". You will discover that nefarious > > tapping practices are institutionalised beyond anyone's ability to > > eradicate. ;-) > > > > The text at the OSG calculator, cited upthread: > > http://www.osgtool.com/Technical.asp?tid=1&id=1 > > is also relevant. To wit: > > > > » > > To minimize tapping problems and lengthen tool life, use the largest > > drill possible to produce a minor diameter that will result in the > > lowest percentage of full thread consistent with adequate strength. A > > minor diameter that provides a 55% to 65% thread is sufficient for most > > requirements, but in some cases a higher percentage of thread may be > > necessary to conform with the minor diameter limits of the thread class > > specified. > > « > > > > Seriously, once we buy an ISO bolt, we can use it as circumstances > > permit. In industry, you just need an engineer to sign off on that. > > > > Would you like to post the drill size your tables specify for M12x1.5, > > and we'll check the engagement on that? (The table from yesterday > > included only M12x1.75, so does not help Tom, or allow comparison with > > our preferred hole size. ) > > > > Erik > > > > > ------------------------------------------------------------------------------ > > Site24x7 APM Insight: Get Deep Visibility into Application Performance > > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > > Monitor end-to-end web transactions and take corrective actions now > > Troubleshoot faster and improve end-user experience. Signup Now! > > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > --- > Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft. > http://www.avast.com > > > > ------------------------------------------------------------------------------ > Site24x7 APM Insight: Get Deep Visibility into Application Performance > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > Monitor end-to-end web transactions and take corrective actions now > Troubleshoot faster and improve end-user experience. Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
