OSG, referenced earlier by John Thornton, has this tool (http://www.osgtool.com/Technical.asp?tid=1&id=1) that calculates hole size given Major Dia, Pitch, and Engagement (% of Thread). Their numbers seem to be slightly different than Erik’s though, but they suggest 60-70% engagement for deep hole tapping.
For example: > On Jan 23, 2016, at 7:31 AM, Erik Christiansen <[email protected]> > wrote: > > Or in general: # d is full thread depth. > Drill Size = OD - (E*2d) # E is e.g. 0.65 > # d = kP , where P is thread pitch. > > Or transposed for E: E = (OD - Drill_Size)/2d > > k is: ISO Metric 0.613 > UNF/UNC 0.613 > # British Association BA 0.600 > # BSW, BSF, ME (32 & 40 TPI), Whitworth forms 0.640 > # BSB, and BSP parallel. > > ---------------------------------------- > > So for M12 x 1.5: > > d = 0.613 * 1.5 = 0.9195 > E = (12 - 10.5)/(2 * 0.9195) = 81.5% > > That's too much, especially for a deep hole. The 10.7 mm hole: > > E = (12 - 10.7)/(2 * 0.9195) = 70.6% > > would give Tom's spindle a fair chance. The OSG tool gives 10.7mm at 66% engagement (for 12mm 1.5). -Tom ------------------------------------------------------------------------------ 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
