split dies?

What is the purpose of the split in a die? Are split dies somehow better than unsplit ones?

In my (limited) experience split dies just break more easily, is there an advantage I am missing?

Reply to
Peter Fairbrother
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It allows you to adjust the diameter of the thread that you're cutting. Main advantage being you can open up the die so the first cut isn't so deep, then gradually close it up until you get a suitably sized thread.

Reply to
Moray Cuthill

I am no expert but according to Peter Wright "Model Engineering

foundation course" the split is to give a little bit of adjustment o the size of the thread.


-- amcne

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Reply to

Peter Fairbrother said

There is a major advantage Peter.

The object of the split is to effect fine adjustment of final component size but also makes for easier use.

By tightening the Die Stock 'wedge' (on the end of the handle, inside the body) into the split the diameter cut will be increased. This would normally be the first pass.

Withdrawing the 'wedge' a little and at the same time tightening the two grub-screws, makes the cut diameter smaller and the second (and subsequent) passes take a much smaller cut producing an improved finish.


Reply to

Size adjustment. This is within small limits to adjust the fit of the thread.

Reply to
Neil Ellwood

The correct way to do a matching thread assembly is to tap the hole first then thread the bolt / stud to suit.

The reason behind this is that a tapped hole is dimensionally linked to the tap. Unless you have oversize or undersize taps these should be standard on size.

Once you have a tapped hole as a guide you then thread the bolt / stud with the die opened out , try it and then close up to get the required fit needed to the fixed tapped hole.

A lot depends on the quality of the tools concerned and also on the sizing of the die holder. Some of the cheap ones are too big on the OD and can easily allow the die to open up too much and crack.

-- Regards,

John Stevenson Nottingham, England.

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Reply to
John Stevenson

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