Yarn needles are essential for certain yarn work. If you crochet (or knit), then most likely it has come up. Yarn needles are required when weaving in ends, assembling granny squares, or sometimes when adding surface stitches or embellishments. Yarn needles are where crochet and sewing meet.
Can you use a crochet hook instead of a yarn needle?
You can use a crochet hook, for best results, use one one or two sizes smaller than the hook you used to make it. That way it can just slip inbetween the stitches.
What kind of needle do you use for yarn?
The gauge is about 5 1/2 stitches per inch and is usually knit on a U.S. 6 needle. Worsted Weight This is what is often considered ordinary knitting yarn. The gauge is roughly 5 stitches per inch on a size 7 or 8 needle. Some worsted may give a gauge of 4 or 4 1/2 stitches per inch and be knit on a 8 or 9.