They are called circular needles and they are used in exactly the same way as straight needles.
You can if you seam up the side and it it is a great thing to do for beginners when you have the right pattern, which is the difficult part. Alternatively, if you do not wish to use circular needles you can use DPNs (double pointed needles) to knit in the round. Often in hat patterns which use circular needles you will need DPNs anyway, so it is good to have some of these when you knit in the round.
well i find it hard to explain but if you go on to youtube.com and type in knitting with circular needles
Yes, it is just describing the material the needles are made from. The most common modern needle types are metal, acrylic, and bamboo.
Note: round needles are almost always called circular knitting needles. In some cases, circular needles will work just as well as double pointed needles. But more often than not, only double pointed needles will work. Why? With double pointed needles, one can knit with as few stitches as they want. This makes them ideal for knitting the tops of hats, which are decreased to a very few number of stitches, and other items where few stitches are knitted. However, if one is knitting with a large number of stitches, then circular needles will work fine, maybe even better, but circular needles have a "minimum stitch limit." Thus, they only work if the pattern works with lots of stitches. So in order to figure out whether circular knitting needles will work for your pattern, read through the instructions, and determine the point at which there will be the least number of stitches on the double pointed needles. Try to estimate the lowest number of stitches that will work comfortably on the circular needles, and decide if the stitches in the pattern will fit on the circular needles.
Yes.
Yes. If you have regular sized circular needles, you'll do better with two at a time. There are now circular needles for smaller projects that work really nice on tight spaces or tiny projects. Still I recommend double pointed needles to make socks. because it will be easier to handle the markers for the decreases and the heel if you are making it with short row.
Circular needles word the same way as regular needles. The cast on, and the cast off, and the knit and purl are all done exactly the same way. Just follow the directions on your pattern, or do the way you always have.
They're no harder to use than riding a bike is. They may feel awkward at first, but once you get used to them you'll wonder what you ever did without them.
No, this is an information site, not a business.
Yes, probably.
Safety guidelines of circular knitting needles can be found online, on informative websites and forums about knitting. A good website that provides various guides is eHow and wikiHow. There are also specialist forums, such as KnittingHelp.