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View Full Version : star pusher thread pitch ?



mike in co
05-23-2010, 01:43 PM
ok cant find my thread pitch gage, so you guys are up...

trying to make a sizer die puller.

thanks
mike in co

59stude
05-23-2010, 04:58 PM
1/2" X 27 tpi.

59stude

mike in co
05-23-2010, 08:55 PM
thats just plain rude.....

garandsrus
05-23-2010, 10:00 PM
Mike,

I purchased a die to cut the1/2 x 27 threads for several punches. It worked great.

John

dragonrider
05-23-2010, 10:20 PM
If you have a 22 cal. size die, make your puller a 10-32, so's it will fit through the die.

deltaenterprizes
05-25-2010, 09:44 AM
Dragon rider, thanks for the tip, now I have to make another one!

mike in co
05-25-2010, 11:29 AM
well with the potential for more pushers and a couple of pullers , i think i'll buy the die.


thanks
mike in co

deltaenterprizes
05-26-2010, 09:52 AM
Do you have a lathe?

mike in co
05-26-2010, 10:03 AM
Do you have a lathe?

yes......26 and 28...no 27

dragonrider
05-26-2010, 12:03 PM
You won't find too many lathes that will produce that thread pitch, that is why Star used it. However buying a die makes it a simple matter. Make your punches from some 12L14 and they will look great too. I use .750" dia stock and turn the thread end first, thread it, knurl the .75 dia for a bit over .25 length. Then turn the piece around hold it in a collet and turn the punch end. I make a punch for each die I make and the length is carefully determined to work with one boolit. I make a new die and punch for each boolit.

deltaenterprizes
05-29-2010, 11:29 PM
My lathe does not have it either but with a simple gear swap I was able to get the lathe to produce the 27 TPI pitch. My lathe has settings for 4 1/2, 9, 18, 36. All are multiples of 9 ( .5, 1, 2, 4, )and so is 27. The gears in the train are normally 60,120,60. By changing the first gear to 40 to make the train 40, 120, 60 and setting the lathe to cut 18TPI the 40 tooth gear increased the 18 TPI pitch to 27 TPI. A train of 52,120,78 would do the same thing.
It takes a little figuring and Machinerys Handbook older versions have a whole section on figuring gear trains. If you can figure ratios you can figure it out.

Star used that pitch because in the 1930s that was a common pitch, the same as a 3/8 pipe thread, still used today. That is like the threads on the old rifles trigger guard screws is 1/4-24 and #12 was a common screw size. Engineers and accountants looking to save dollars change things. We are supposed to be all metric by now and it is slowly happening.

JIMinPHX
05-30-2010, 11:14 AM
If you use a die, see if you can turn a pilot diameter on the work piece to get the die started straight & concentric. It makes a big difference.

HeavyMetal
05-30-2010, 11:48 AM
Garadsrus:
Where did you puchase the die?

scb
05-30-2010, 08:15 PM
HeavyMetal I got mine here-> http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=17742538&PMT4NO=86615818

HeavyMetal
05-30-2010, 11:19 PM
Tanks!

mike in co
06-01-2010, 02:02 AM
mine is comming from travers tools

HeavyMetal
06-04-2010, 09:52 PM
Found one at the local Rutland tool!

garandsrus
06-04-2010, 10:17 PM
I found the die at a local tool shop. Saved on shipping.

John