Problem identifying a thread

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Dave, looking at your photo, to me it looks strange and as others have said, it may be a double start. While they were posting, I've taken a photo of a M10 threaded rod and have stitched part of your photo just above it and to me the angles of the threads look different. I know it may be due to camara angles and all that, but the two rings around your thread at the very start may suggest a double thread.

Regards Nick.

[Dave CastleParticipant @davecastle60484]

Well done Ian. Brilliant. Just checked and it is a 2-start thread. Something I never considered.

Can't even begin to think of what that means if I want to make one! Will have to think about it.

Thank you all for your help.

Cheers

Dave

[Sub MandrelParticipant @submandrel]

Lightbulb moment!

This isn't the thread that goes into the camera – it's the other end that fits into the clamp that holds the ball mount to the top of the tripod, hence the use of a quick 2-start thread and no need for compatibility.

Neil

[SaxalbyParticipant @saxalby]

I thought we were talking about the camera mounting thread.

Check my head again and the clamp thread is indeed a 2 start thread 10mm X 1.5mm pitch 3mm Lead

Barry

[Ian S CParticipant @iansc]

The two start thread, that size is not too hard, or too technical to make on the lathe, made one for a part for the hood on a vintage pram, for our museum, made with the nut 10k away it fitted first try, there are two of these bolts, and now I can't work out which is which. Ian S C

[Michael GilliganParticipant @michaelgilligan61133]

Perhaps the most revealing aspect of this discussion is Dave's original comment:

[quote] A piece of M10 all-thread fits the stud like a glove. Angle, pitch and thread depth all match. [/quote]

Now that we know that the long stud has a two-start thread: That tells us an awful lot about the loose tolerances on commercial all-thread. … Worth remembering!!

MichaelG.

 

Edited By Michael Gilligan on 05/01/2014 11:04:00

[Nicholas FarrParticipant @nicholasfarr14254]

Hi MichaelG, but his M10 x 1.5 looks as if it fits like a glove also.

Regards Nick.

[Michael GilliganParticipant @michaelgilligan61133]

Nick,

That's not what I thought. [see quote below]

… I suppose it depends how well your gloves fit

MichaelG.

Posted by Michael Gilligan on 04/01/2014 17:34:52:

Dave,

That's certainly nearer to M10 x 1.5 … although it still doesn't look quite right.

It may be an illusion, but it appears that the contact area changes from one flank to the other;

.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi MichaelG, I take your piont, however when comparing a tap against a full thread you get a clearer view than when comparing two full threads together.

I must have used a mile or two of "all-thread" in my time and have never noticed any significant difference between that and good quality bolts, but then it has always been industrial grade and not the toy town stuff you can buy at rip off prices from DIY stores.

Below is a piece of all-thread compared to a bolt, a bolt compared to a Goliath M10 x 1.5 tap and a piece of all thread copared to the Goliath tap with my USB microsope. I cannot see any significant difference between them.

Regards Nick.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, Nick

Very helpful photos.

At least that confirms that some decent all-thread is available.

MichaelG.

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