Cutting a 6-32 UNC thread on a lathe?

[Ed DuffnerParticipant @edduffner79357]

Hi everyone,

If I wanted to cut (single point) 6-32 UNC threads on the lathe, how does that transpose to lathe language?

Thanks, Ed.

[Ed DuffnerParticipant @edduffner79357]

[Michael GilliganParticipant @michaelgilligan61133]

32 tpi, 60°

.

Edit: More detail here

Edited By Michael Gilligan on 16/03/2016 11:28:43

[Ed DuffnerParticipant @edduffner79357]

Thank you Michael, that should do the trick

Ed

[Neil WyattModerator @neilwyatt]

The only important bit is the 32 – set the gearbox/change wheels for 32 threads per inch.

You can look up the major diameter and minor diameter in tables easily found on the web. Depth =major-minor/2.

Either grind your own tool or get one with a suitable profile, which is based on a 60-devree vee with a rounded end.

Neil

[Ed DuffnerParticipant @edduffner79357]

Thanks Neil, I'm ok for the 60° bit. I'm making an extra insert / mandrel thing (whatever it's called) for a Rivnut insertion tool. The other end of the mandrel and it's sleeve are LH threads, metric I think, which I should be ok with.

Ed.

This  is an existing metric example.

 

 

Edited By Ed Duffner on 16/03/2016 12:34:11

[Roger HeadParticipant @rogerhead16992]

What material are you using for the mandrel, Ed? I cringe at the force I have to use with some of my M4 Rivnuts. I keep telling myself "it's going to break, it's going to break" … but it hasn't yet!

Roger

[Nick WheelerParticipant @nickwheeler]

Posted by Roger Head on 16/03/2016 23:27:41:

What material are you using for the mandrel, Ed? I cringe at the force I have to use with some of my M4 Rivnuts. I keep telling myself "it's going to break, it's going to break" … but it hasn't yet!

Roger

Are you using the tool that 'works' like a pop-riveter? They're crap.

One of these **LINK** looks expensive, until you use it to install a bunch of steel M8 rivnuts.

[John Stevenson 1Participant @johnstevenson1]

Jesus,

 

£99 for a fancy allen key and screw ?????????????

And stand there all day winding ?????????????????????

 

Wouldn't work for me, most of my Rivit nuts go into closed spaces so you can't see how much it's compressed.

You need a tool that snaps off at the right tension.

 

Anything up to M6 the modern battery drills with a clutch manage these very well and very fast.

Edited By John Stevenson on 17/03/2016 00:06:08

[Ed DuffnerParticipant @edduffner79357]

Hi Roger,

I'll probably use silver-steel, harden and temper it. That's the plan anyway

Nicholas, The tool I have is like the riveter with an integrated depth stop. It's only being used for small computer case screws initially so it should be quite manageable. The hard part is finding a uk source for 6-32 rivnuts. I found one called memfast who want £8 for 25, or there's an Ali-express source, 100 for just over £10.

I did wonder what material steel rivnuts were made of, soft enough to compress, but hard enough so the thread doesn't strip. I magine there is some kind of weak point to allow creasing around the wall.

Ed.

[Roger HeadParticipant @rogerhead16992]

Nicholas, yes, the tool brand is Avdel, and as you say, is essentially like a pop-riveter with 300mm handles. But I don't see how the tool itself can be faulted – the adjustment and the action are free, and it seems to me that the problem is simply the amount of force that is required to collapse some of the inserts. The inserts are supposed to be genuine product, purchased over the last 20 – 30 years. But I sure do worry about that M4 mandrel.

Roger

[Ian S CParticipant @iansc]

I see that the mandrels are grade 12.9 cap screws, that 's fairly tough stuff.

Ian S C

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