sorry steve i had to look that up.. What is the purpose of knurling? Knurling allows hands or fingers to get a better grip on the knurled object than would be provided by the originally smooth metal surface. Occasionally, the knurled pattern is a series of straight ridges or a helix of "straight" ridges rather than the more-usual criss-cross pattern. Ok i got it now, just i had never heard of it before,,lol