What Is Knurl?

Knurl is a pattern of raised ridges or indentations created on the surface of a metal part to improve grip, enhance aesthetics, or facilitate mechanical bonding between components. It is a common manufacturing process used in machining, where specialized tools press or cut patterns into the material's surface. 

How Knurling Works

Below are the knurling tools：

And here is the knurling tool installed on the lathe:

Knurling works best with ductile materials that deform easily, such as aluminum, brass, copper, and mild steel. Harder materials like stainless steel, tool steel can be knurled but require sharper tools and higher pressure.

Knurls come in various standardized patterns, categorized by their shape and orientation. The most common types include: straight knurls, crisscross knurls, radial knurls, and custom knurls.

Below is different pattern knurls:

Advantages and Considerations

Advantages: Improves grip without adding bulk, enhances part durability, and can be done quickly in production.

Considerations: Excessive pressure during knurling may cause material distortion or cracking, especially in thin-walled parts. Hard materials may require pre-softening (annealing) or post-processing to maintain strength.

Knurl is a functional surface texture created through plastic deformation, designed to improve grip, usability, and mechanical performance in countless industrial and consumer products. Its versatility in patterns and materials makes it a staple in manufacturing.

Ningbo Joyo Metal Products Co., Ltd. also specializes in providing knurled surface treatments for metal parts, offering precise control over patterns, from standard diamond or straight knurls to custom textures tailored to grip, functional, or aesthetic needs. Beyond knurling, our surface processsing capabilities extend to a comprehensive range of treatments, such as sandblasting, anodizing, chroming, powder coating, ensuring we can meet diverse industry requirements for performance, durability.