Fused Quartz and Threads

Inside or outside threads?

You MAY be able to grind threads on the OD of the tube with a diamond wheel. The ID is questionable.

It maybe could be annealed, but you'll need to supply much more detail.

Corning makes Macor, which is a machinable glass-ceramic. It's non-pourous, so it could function as a test tube with threaded ends.

http://www.corning.com/specialtymaterials/products_capabilites/macor.aspx

I have never come across this as general applications I have seen (using fused quartz tubes?) just use press or captive loose-fit to hold the bare tube in place and compensate for different material thermal expansion rates (for example radiant heater elements).

Could you use a press-fit adaptor instead?

What exactly is the application?

Looks like it is possible...

No more info here. Maybe a clue for further Googling in there.

Try to keep it simple for me, I do not have much knowledge with terms LOL. Here is the picture of an example, this small tube is made of polycarbonate, the picture purposes is just to show you the threadings I am having in mind to cut on the Fused Quartz.

http://img.photobucket.com/albums/v155/blecap/IMG_20120906_153737.jpg

Your search - http://img.photobucket.com/albums/v155/blecap/IMG_20120906_153737.jpg - did not match any documents.

Couldn't make it work.

Apology, but do u mean u can't open the image or its impossible to cut it?

Can't open the image.

It should work now, please try again, sorry about it.

I have not done this but there may be three approach one can take

1. Use high temperature threading using diamond threading tool. Temperature needs to be above glass transition temperature which is 775oC and then cool slowly--> Non doable

2. I prefer coating and making Patten and then etching it out to make thread --> doable and commercially feasible

3. Using diamond bit make thread and then blunting cracks and annealing --> high risk manufacturing and non proven

My vote is for the glass-ceramic. It is developed for mechanical application, including thread cutting.

Glass tubes, including quartz are left with considerable internal stresses, that a glass technician can weld, bend into a desired shape. But thread cutting of the normal shapes (V shape, trapezoidal) produces sharp edges. Those are excellent way to start fractures from very low mechanical loads.

Look at a better chemical lab setup. Most if not all is custom work by the glass technician. No thread in sight, but plenty of gastight fittings with polished-in conical sections.