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Single point threading M1 x 0.25. Anyone done it?

implmex

Titanium
Joined
Jun 23, 2002
Location
Vancouver BC Canada
Hi All:
I have some 1 mm diameter stub shafts to make: 0.200" long with an M1 x 0.25 thread for 0.086" long on one end.
The desired material is 17-4 PH at condition H900.

What are my chances of pulling it off by single point threading it instead of trying to threadmill it?

I ground a nice little carbide tool for it: 15 degrees relief on the leading flank and 5 degrees of relief on the trailing flank with zero rake so I'm good there.

I can have a couple of turns of thread runout, so no relief groove needed.

Would you turn it in 2 stages or do you think I can get away with threading it to final length in a single go?

Obviously I don't intend to turn the rest of the shaft until the thread is done.

BTW I did try cutting it with a button die...no go, and now I have a fucked up button die:bawling:

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
 

Booze Daily

Titanium
Joined
Sep 18, 2015
Location
Ohio
I’ve done similar though not that small. I started with massively oversized stock and turned it Swiss style.
Turn a little, thread a little. Turn a little farther, thread a little farther, etc.

The size of the stock supports the turning as you go.
 

mattthemuppet

Hot Rolled
Joined
Apr 22, 2016
Location
San Antonio
I swear I have a set of Geometric chasers for M1x0.25 somewhere. Could barely see the teeth. Not that's much help though.

How many passes would you need to do to get the correct thread depth?
 

TheBigLebowski

Aluminum
Joined
Sep 9, 2018
Not sure of your quantity, but I had luck doing 0-80 threads in a 5c grinding whirly. I would use 0.0625 rod - finish grind the diameter - and then put the whirly on a jig that would line up the whirly with the thread button and carefully thread by hand.
 

implmex

Titanium
Joined
Jun 23, 2002
Location
Vancouver BC Canada
Hi again All:
OK I got it to work in free machining brass.
Next is 17-4 PH.
Here's a picture.
I must say I'm getting just exhausted humping that huge stock around.:D
I need a forklift!

For those who are curious; the DOC is 0.0005" at 60 degree infeed.
Last pass is 0.0002" straight in.
I'm threading at 2000 RPM
I do a 2 turn pullout.
A part takes about 45 seconds with slow rapids.
That'll be cut in half when I turn the rapids up...good enough for me.

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com
 

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implmex

Titanium
Joined
Jun 23, 2002
Location
Vancouver BC Canada
Well, Guys; it went totally uneventfully.

I wet my panties for nothing at all.

Total cycle time of 21 seconds per part and they came out nicely...0.0002" difference from the smallest to the biggest.
Now to slice them off the stock with the wire EDM. (the overall length needs to be accurate and wire cutting them is the easiest way)

I need ten parts for the project and I've got thirteen blanks.
All is right with the world!

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com
 

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implmex

Titanium
Joined
Jun 23, 2002
Location
Vancouver BC Canada
Hi Bobw:
I used a toolmaker's microscope on the thread and confirmed with my shadowgraph at 50:1 and a mylar overlay.
I miked the stems with a tenths mike using the eye of faith and some nice confirmation bias.

You are correct, this is a "does it fit" kind of project, not a "here's the tolerance" project.
I don't actually know what true size the thread pitch diameter is with all that much certainty, but I do know they all came out very close to the same using the methods I measured with, and they all fit the mating thread very nicely.
For this project, I'm calling it a win.

I expected it to be quite a bit worse; especially on the 17-4 PH at H900, but that stuff does turn beautifully at 6K RPM, even at those skinny diameters, and didn't really deflect at all during threading even though I expected it to, especially on later parts as the tool could be expected to get dull.
I did have to finish turn the diameter with a brand new dead sharp insert with a 0.0078" nose radius to keep the shaft parallel...my 0.0156" rad roughing tool left the shaft 0.001" fatter at the free end (understandably).

So if you asked me to make a thread like this to a tight tolerance, I'd probably have some significant trouble.
I used a home made cutter whose precision is questionable at best, I gauged the pitch diameter by "does it fit" and I looked at them after they were done to see what I got.
What I got was a nice surprise.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
 

TeachMePlease

Diamond
Joined
Feb 11, 2014
Location
FL
So if you asked me to make a thread like this to a tight tolerance, I'd probably have some significant trouble.

Not once you bought the right equipment. Thread whirl it all day long, no worries.

I can make it easy on my equipment. I'm not sure I could make it at all with your equipment. So you win, hands down. Nice work, Marcus.
 

implmex

Titanium
Joined
Jun 23, 2002
Location
Vancouver BC Canada
You know, TeachMePlease, I was thinking of you and all the toys you get to play with while I was making them, especially since I recall you saying once upon a time that you really like working with 17-4 PH at condition H900, and I was dreading single point threading it.

I remain envious as Hell of all your goodies, but I did pray to your avatar with that magnificent hair of yours, and it seems to have worked...so thank you!:D
Next time I have crazy shit to turn, I'll be sure to do it again!

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
 

Screwmachine

Titanium
Joined
Mar 8, 2001
Location
Switzerland
To Milland and 70olds- Schurch have some decent English speakers there and will definitely sell to any country, really nice folks. Only source I know for Yamamoto HSS drills too, fantastic stuff down to 0.10mm, (for tricky work it's Dixi Polytool carbide). I don't know what Habegger's international presence is like; it's really odd, but it's like a lot of Swiss companies don't gaf about anything outside this country. Thankfully there are companies like Schurch that _do_.
 
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plastikdreams

Diamond
Joined
May 31, 2011
Location
upstate nj
You know, TeachMePlease, I was thinking of you and all the toys you get to play with while I was making them, especially since I recall you saying once upon a time that you really like working with 17-4 PH at condition H900, and I was dreading single point threading it.

I remain envious as Hell of all your goodies, but I did pray to your avatar with that magnificent hair of yours, and it seems to have worked...so thank you!:D
Next time I have crazy shit to turn, I'll be sure to do it again!

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

17-4 is such a great metal to work with.
 

Bobw

Diamond
Joined
Feb 8, 2005
Location
Hatch, NM Chile capital of the WORLD
17-4 is such a great metal to work with.

Its #4 on the list of essential materials.

#1) Delrin

And if it needs to be stronger

#2) 2024 or 7075. 6061 if you need to weld it.

And if it needs to be stronger still

#3) 303, and if you need to weld it, see #4.

and if it needs to be stronger still.

#4) 17-4

That should cover 95% of all machined parts ever needed..
 

barbter

Diamond
Joined
Oct 27, 2007
Location
On Tour...
I remain envious as Hell of all your goodies, but I did pray to your avatar with that magnificent hair of yours, and it seems to have worked...so thank you!:D
Next time I have crazy shit to turn, I'll be sure to do it again!

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

I hope you remember what briefs you were wearing too Marcus!
Who says there's no place for superstitions and "lucky threading briefs", in engineering :D
:cheers:
 

doug925

Titanium
Joined
Nov 21, 2002
Location
Houston
Its #4 on the list of essential materials.

#1) Delrin

And if it needs to be stronger

#2) 2024 or 7075. 6061 if you need to weld it.

And if it needs to be stronger still

#3) 303, and if you need to weld it, see #4.

and if it needs to be stronger still.

#4) 17-4

That should cover 95% of all machined parts ever needed..


I wholeheartedly agree with your list, but I would add 4140 CHT as #3. :D
Outside the 6061 (which we machine almost daily) the predictability of the listed materials lends to a stable process.

Doug
 








 
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