Big yarn, smaller needle...can I do that?

Still a newbie knitter here and most of what I am learning now I am getting from books and teaching myself from videos so there are still somethings I just don’t know.
I found this great yarn but it is chunky and I usually knit with DK or worsted yarn and use the ‘right’ size needle or just slightly bigger or smaller. I will be making a hat out of it maybe using a simple pattern out of a new book I got or just using my circular knit hat pattern I use all the time.
My question is, can I use 5.5mm needles for this yarn that calls for 10mm needles on the band as long as I knit a gauge and determine how big it will have to be for the co sts or do I need to go buy bigger needles? How much can you manipulate what a pattern is calling for (with regards to yarn) or what the band says?
Thanks in advance.

you can go pretty far in either direction. But that step seems a little big. You will have to fit the yarn through the stitches, you know?

Do you already have the yarn? If so, give it a try and you will find out, how it goes.

5.5mm ist not really all that small… but 10 is a huge diffence.

If you knit with smaller needles than needed (mostly the size that is called for or something similar) then your fabric gets denser. If the difference is so big then you might end up with something very stiff and weird. Maybe you will find out about that with a swatch, best of all.

But eventually it will make sense to own needles in different sizes to do every project justice.

So in US sizes that’s a 9 and a 15? … Going up or down a couple sizes is usually fine depending on how you knit (tight or loose), but the difference between those two sizes is very large. I think the fabric you’ll end up with would be very stiff unless you’re an incredibly loose knitter. To find out for sure though the best thing you can do is knit a swatch and see how the fabric feels to you. If you like it go for it.

Here’s a hat calculator that you can create any hat with any gauge yarn. You’ll still need the correct needle size for your yarn though.

Thanks, I never thought about having to fit the yarn through the stitch. As I already have the yarn i’ll do a test swatch for fun but look for some needles either the right size or a lot closer.
Thanks again

You can, but it’s going to be really stiff and the sts will be tight and it’ll be hard on your hands. You also still won’t get gauge because the yarn is physically twice as thick as in the pattern.

Thanks all,
I will forgo bothering to do anything with this yarn until I can get the right size needles. I had a vague idea how changing needle sizes would change the knitting but didn’t realize just how much if too big a change. I just get so excited when I get a new yarn I like I have a hard time containing myself.