thread depth

[sethren]

Can anyone tell me please what the thread depth, ( core depth ), is on a 5 inch diameter @ 12 tpi ?

Is there a formula ( i know there is ) its just such a rare occurence that I need to use it that I have forgotten it or how to obtain it !

seth

[Geof]

Google is your friend. This is one of the links that came up when I Googled "thread depth calculation".

Stop Scratching Your Head and Make Some Chips !!

Scroll almost to the bottom of the page.

[sethren]

thanks Geof. Do you think that threr's much difference between the 60 degree angle, given, and the 55 degree that I want ?
the 60 degree is metric i think and i want imperial.


seth

[Geof]

Whitworth is 55 degrees (I think) but UNC and UNF are both 60. I did a rough calculation and I think the difference will be around 0.002" to 0.003" so I figure you can probably ignore it.

[RICHARD ZASTROW]

Some threads are truncated or have radiused "peaks and valleys" as well.

Dick Z

[sethren]

Yes Geoff your right. Thanks for that.

Seth

[GAGV]

Hi, please i need your help, i need to make a 10-24 and 3/8" NF thread, and i need to know feed rate and spindle speed, i will work in A380 alluminium and stainless steel

thanks

[Shane123]

Originally Posted by GAGV Hi, please i need your help, i need to make a 10-24 and 3/8" NF thread, and i need to know feed rate and spindle speed, i will work in A380 alluminium and stainless steel thanks

this would have been easier to get replies if you had started a new thread. your feed on a lathe will be IPR, so take 1 divided by the number of threads per inch, and that is your feed (example 5/16-24 thread would have a feed of .0416 per revolution, aka F.0416). as for speed, I usually start off around 1500 rpm, unless there is alot of part hanging out from the spindle, then i slow it down to resolve chatter & keep tool life, when using inserts. if your using a tap, slow it down to 150-500, depending on material and how well you trust your spindle/turret coordination.