Cylindrical parts, such as screw heads, round nuts, gripping surfaces on measuring tools and all kinds of handles or grips which have to be gripped firmly, must have roughened gripping surfaces. Good grip of such gripping surfaces of operating elements is ensured by providing them with knurled portions. According to the patterns produced, the knurled portions are called straight knurling, cross knurling or spiral knurling.
Figure 1 Straight knurling
Figure 2 Cross knurling
Figure 3 Spiral knurling
This non-cutting technique is no real turning operation. As an embossing operation it belongs to the metal forming techniques, but it is done on the lathe and is a very simple and cheap method.
Gripping surfaces thus produced are sufficient in terms of
- accuracy to size
- shape (good grip)
- surface finish and