A really oddball twin lead M6 bolt wanted

[Ian PParticipant @ianp]

This is to replace an existing damaged bolt on an imported bit of camera mounting hardware (dovetail plate and clamp) which fits on Tripod for easy camera swapping.

The damage was caused by me not realising is was a two start thread when trying to remove the locking compound with a standard M6 Die.

Long shot, but I just thought I would see if any one had an oddment in their collection?

Ian P

[Ian PParticipant @ianp]

Two start M6x1 about 40mm long

[Ian ParkinParticipant @ianparkin39383]

Hard to imagine that you will find another except from the same equipment…I can knock you one up if you cant ?

So its 6mm 2mm pitch twin start?

[Dave MartinParticipant @davemartin29320]

Posted by Ian P on 20/01/2018 14:38:52:

This is to replace an existing damaged bolt on an imported bit of camera mounting hardware (dovetail plate and clamp) which fits on Tripod for easy camera swapping.

The damage was caused by me not realising is was a two start thread when trying to remove the locking compound with a standard M6 Die.

….

Ian – could I just interject – are you sure it's M6? only reason for asking is that the vast majority of the actual camera and tripod fittings are either 1/4 (UNC if I recall correctly) or 3/8.

Dave

[Ian PParticipant @ianp]

I never thought about screwcutting one myself and its probably not worth the effort, it will be much simpler to change to a standard M6.

The bolt passes through a loose dovetail clamp plate with the end of the bolt loctited into a blind hole (so the nut is captive) I wanted to machine down the bulk of the knurled nut so unscrewed it. The Chinese locking compound was incredibly tough and hard to remove and the female thread in the aluminium now looks far from pristine. Now I have it apart I can just make a new knurled nut to the size and shape there is room for.

The device itself is dovetail type (Arca/Manfrotto) quick release and the fastenings to the tripod and camera are standard 1/4×20 and 3/8×16 (the photographic industry are not too fussed about thread form and dont differentiate between UNC and Whit).

I did think it highly unlikely that anyone would have such an odd bolt lying around

Ian P

[Ian S CParticipant @iansc]

I made a 1/4" BSW two start thread without having the nut to try it on, two 10 tpi threads 180* apart, fitted first go, it's one of a pair, but don't ask me which is which, I don't know. Actually it's part of the stay that holds up the hood on a vintage pram in our museum collection.

Ian S C

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