Back to Home Page of CD3WD Project or Back to list of CD3WD Publications

		Knurling - Course: Techniques for machining of material. Trainees' handbook of lessons (Institut für Berufliche Entwicklung, 19 p.)
			(introduction...)
			1. Purpose and meaning of knurling
			2. Design and types of knurling tools
			3. Preparation of knurling
			4. Straight knurling of small widths on simple cylindrical parts
			5. Spiral knurling of small widths
			6. Cross knurling of small widths
			7. Straight knurling of convex parts
			8. Spiral knurling of big widths

1. Purpose and meaning of knurling

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
- fit.