The key gauge for worsted weight is 5 sts =1". Needle sizes may vary from a US 6 to US 9. It is used for knitting everything from afghans and baby clothes to medium weight sweaters and mittens. Aran weight is a sub category of worsted weight. It generally refers to yarns that knit at 4.5 sts= 1" on US 8 needles and may be referred to as heavy worsted.
The yarns in this catagory are wool yarns.
