Thread: single point internal buttress threading

When cutting an internal buttress thread on a manual lathe, how do you set your compound? I want to make a drawbar and nut for a 20 mm buttress collet.

thanks
Markus

It's been a long time....I'm assuming a RH thread....I set the compound to just scrape the 7 degree flank and do most of the actual cutting on the 45 degree side of the thread. So, for an internal thread I set the compound over about 7 degrees to the left. It's a fragile tool; so take light cuts and take your time.

Make the male thread first if don't already have it and use it for a gauge.

Andy Pullen

I have alway's set the compound at 45.Then take your flat,5,7 and add the 45. Then grind your tool 1 degree less than the sum of the angles. Then set the flat ,5,7 to it's proper location.Set # thread's per inch.Note the tool will only cut on the advancing face as it goes down the 45.That's the way I do it.
jim

Put a flat on the tool to match the flat on the male thread.

Markus - take a good look at the thread. It would help if you can come up with the manufacturer of the machine or the collets. See if you can find a DIN number.
Most used are DIN 513 . Here are the specs:http://www.gewinde-normen.de/en/butt...se-thread.html
This would have a 30 deg. and a 3 deg. angle.
Here is DIN 513 fine thread:http://www.gewinde-normen.de/en/butt...ne-thread.html
Some use a Acme thread DIN 6341
You find it here:http://www.gewinde-normen.de/en/trap...ne-thread.html
Here is the complete info page:http://www.gewinde-normen.de/en/index.html