Anyone know what this screw is called?

It is probably manufactured specifically for the bottle holder and may not be generally available as a hardware item.
However a very similar product with a circular shaped end known as an "Eye Bolt" and generally available in hardware stores in a variety of thread sizes and lengths.

"Over Centre Latch" is one name that comes to mind, most likely lots more names.

Cheers, Gaz.

It's called an "over-centre latch". You can usually buy the hook side seperately but you may well need to buy the whole latch for the screw eyelet.

Look here;Struts Australia - Over-centre Latch


Cheers Mick

Excellent! Thank you.
Over-centre latch it is :)

Bunnings have some and ships chandelery carry them.
How much longer do you need . I can see 20mm if you re drill those two screws.

Geez, did any of youse blokes actually read the OP's statement.... "it is the adjustable screw".............. he is wanting, but longer.

Not the whole over-centre latch, not the legs........ just a "longer screw".

Thanks PJR, at least you could see it!

Here's a link to one supplier:

http://www.strutsaustralia.com.au/products/over-centre-latch

Cheers

You probably won't buy one separately but you could use a barrel nut and thread to extend what you have

I just came across the same thing by a different name - a toggle latch.
http://www.bunnings.com.au/search/products?q=toggle%20latch
I was hoping to just buy the adjustable screw/bolt part but as suggested it seems they come as a kit. Considering it's only because it won't close around the gas bottle as is at the max of the thread, and the current bottle is about 5 years old, I think searching for a bottle to fit might be a better option than mucking around with the clip.
After doing a bit of reading about others' experience with bottles not fitting holders it seems this is somewhat of a common problem.
P.S the photo above is not my exact one - just a google image I found to try and explain it but you were all right on the money.
I appreciate your help (PPS I'm a she not a he but that doesn't matter I hope).

Can you undo the 2 phillips head self tapping screws and move the bracket forward then re screw it. Looks like you could nearly get 20mm.

Hey mate
You could try this guy, I've had dealings with him and he's good

http://www.ebay.com.au/itm/201056078632

Cheers
Bill

As already suggested, you could pick up a centimetre or 2 by moving the handle along the strap. If that's not enough, you could extend the circular strap by screwing a longer strap inside the existing one.

Cheers

John

If you don't have any luck with the leads provided why don't you get a metalworking shop to make one with a longer thread. I wouldn't think it would be too expensive.

Nev

I wouldn't mind a longer screw either, but it does seem to be an overlatch mechanism.