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Mike Amick
09-26-2013, 12:31 AM
I can't find the post where someone mentioned how to either calculate or
pointed to a chart that told you how deep a thread should be from the
major diameter. Hope I am wording that right.

Mike

mf205i
09-26-2013, 04:48 AM
Second link, Atlas book has thread charts
You might find these links interesting or useful
First go to Tonyís site, http://www.lathes.co.uk/page21.html
Then start with these.
http://www.scribd.com/doc/34415359/Manual-of-Lathe-Operations-and-Machinists-Tables-Atlas-Press-Co
http://www.bbssystem.com/manuals/Lathe-Tutorial.pdf
http://www.youtube.com/watch?v=cBYQmaeI-VU Watch all of the Tubalcain videos.
http://www.wewilliams.net/SBLibrary.htm
http://southbendlathe.org/?tubepress_page=1
http://techtv.mit.edu/collections/ehs-videos/videos
http://www.archive.org/details/textbookofadvanc00smituoft
http://metalwebnews.com/machine-tools/fmt.html
http://www.bbssystem.com/manuals/Navy-Machinery-Repairman.pdf
See HTRAL at http://www.wswells.com/index.html
http://www.jjjtrain.com/vms/library.html
https://rdl.train.army.mil/soldierPortal/soldier.portal
http://www.sherline.com/grinding.htm
http://www.formrolldie.com/new_page_1.htm
http://bbssystem.com/viewforum.php?f=12&topicdays=0&start=0
And donít forget to download your FREE copy of Machineryís handbook. Edition 5. http://books.google.com/books?id=VkEYAAAAYAAJ
And if you have an Atlas or Craftsman product.
http://www.roseantiquetools.com/id116.html
Have fun, Mike

J Tiers
09-26-2013, 08:33 AM
This comes up a lot, and probably is fine for very non-critical threading.

But the real deal is either to use a gauge, which could even be the matching nut, or to do the depth to dimension, which means the pitch diameter. You measure the pitch diameter with a mic and wires, thread triangles, or a a thread mic, etc.

If you need to make a thread for a nut that you do not have, or you cannot bring to the lathe, you almost have to do it by pitch diameter. That's about the only standard way to describe the thread; thread pitch and pitch diameter.

TGriffin
09-26-2013, 02:15 PM
Mike,

If you are using a sharp pointed tool and feeding with the compound, the distance is .75/number of threads per inch. If you are feeding with the compound and have a proper width flat on the tip of the tool then the distance is the pitch of the thread/1.5. Once you get close to the finish size, I recommend feeding with the cross slide and measuring the pitch diameter of the thread with a thread mic or thread wires.

There is a whole series of videos on my YouTube channel on thread cutting that you may want to check out.

Tom

Mike Amick
09-26-2013, 04:19 PM
Perfect .. thanks.

And I bookmarked your YT chnl .. definitely will check it out.