Steel knitting needles sometimes need to be reground. The best tool that I
have found for that is the little ceramic sharpening stone that Felco sells
to sharpen its pruning shears. It has a groove that runs down one side of
its generaly triangular cross-section. The bottom of the groove is rounded
and makes getting a nice rounded tip easy. I use a bit of WD-40 as cutting
oil

Do not try to regrind aluminium needles.


Aaron