Check out Harbor Frights web site and see if they have a posted instruction sheet for them. the paper that came with one of mine years ago. had you sharpening them with a stone along the cutting edges at the tip and along the opening. have followed the instructions and they have always put the hole and broe the lip in wood and plastic that I use them in.
Been there, probably broke it, doing that!
I am not a lawyer, and never played one on TV!
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