Thread cutting dilema?

Creativechipper said:
Amazon to the rescue thread gauge set and fishtails for 9.99 shipped. https://www.amazon.com/gp/product/B07DC2RKX7/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
Now that will go nice with my Blue Point tap and die set, gotta skimp somewhere..lol
Click to expand...

I hope you realize the one thread gauge is for Whitworth threads, not 60 degree threads like we use here in the USA... The other is for metric.

55 degree threads aren't something that is typically used in the USA.

Ted
 
So looking to thread with 1/4-1/2" tap and dies what tooling measuring tools do I need to be able to cut and measure?
It looks like the screw pitch gauge set for whitworth is useless for my set up.
 
Hi Guys,

I must admit to laziness here and say that I do use carbide threading tips. I also run the lathe in reverse, cutting away from the chuck, and yes I do just plunge straight in. :)
 
Creativechipper said:
So looking to thread with 1/4-1/2" tap and dies what tooling measuring tools do I need to be able to cut and measure?
It looks like the screw pitch gauge set for whitworth is useless for my set up.
Click to expand...

You could still use the thread gauge to help determine 60 degree threads... the threads per inch are still the same, just the profile won't fit 100% because it's 55 degree instead of 60, but it would be close. Usually, you're not trying to determine the profile of the thread when using a thread gauge, just the threads per inch and it should work for that.

The only tools I would say you really "need" would be a set of mics to turn/measure the major diameter, a fish to align your threading tool (or some other means) and a nut to use as a gauge for sizing the pitch diameter of the threads. If you really want to measure the pitch diameter (which I don't 99.9% of the time) you can pick up some thread measuring wires. Something like these: https://www.ebay.com/itm/48-Pc-Thre...573189&hash=item41eb688d86:g:imQAAOSwImRYkSdG But, if it was me, I wouldn't bother with getting any and just use a nut for a gauge.

I would start with the minimum and once you get going and learn more you'll know yourself what you want/need...

Of course you'll also need a thread cutting tool and some cutting oil.

Ted
 
Add remember, as others have said, you don't need a thread gauge. I went a long time without one and just used a 6" scale to count the threads per inch... the gauge is a "nice to have" tool, but certainly not needed to do the job.

Ted
 
whitmore said:
I think the disparity is related to the tool used; if your tool is HSS (and that's the old style), the easiest sharpening
is to make it a left-cutting or right-cutting tool, only ONE of the two edges of the tool is at the optimum height for cutting.
With a carbide insert, a one-edged insert might have a chipbreaker on the left edge but not the right. A symmetric
two-edge insert will cut left and right flanks equally (but it's problematic to include a chip breaker).

For fine vee threads, with HSS tool, and for the relatively heavy chip loads that a single-point tool
does most efficiently, the 29.5 degree setting is still a good choice. If you need special accuracy,
the sideways-load-flex issue might point you to 90 degree plunge cutting (but don't expect the chip
to come out as a nice curl).
Click to expand...

I use the 29 degree setting on the compound. But compound feeding is unnecessary with inserts especially the top notch style. These inserts were designed for CNC lathe threading. Witch uses multiple passes. So you can duplicate that on a manual lathe.

Like the quote it from using 60 degree ground HSS tools where this started and for those tools the compound feed is best


Sent from my iPhone using Tapatalk
 
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