What is Knurling? A Complete Guide for You.

Pattern machining or knurling is an engineering manufacturing process used in modifying the surface of an object and enhancing its grip. It could be realized by cutting or extruding, thereby giving the texture or pattern that would serve non-slippery purposes as well as decorative functions. Normally performed at the steps of machining, fabrication, and design knurling is intended to enhance the operation and looks of the product.

This paper highlights what knurling is all about concerning hand knurling and machine knurling. Different kinds of knurling textures, hand knurling tools and holders, the importance of knurling in machined parts, useful material for knurling, considerations during

Table of Contents

What is Knurling?

Knurling (pattern machining) is an engineering manufacturing technique in which a pattern is created on the surface of an object to give it better-gripping properties. A texture or pattern is obtained by cutting, extruding a workpiece’s surface, and so on. The friction coefficient is increased, which makes it a non-slip object, and it also serves an aesthetic purpose. This is normally done during machining, fabrication, and design for improved functionality of the workpiece or better aesthetics.

Hand knurling and machining knurling

Hand knurling

Hand knurling is also another hand-operated knurl, meaning the texture or patterns are made to enhance grip and aesthetic value. As opposed to automated mechanical Knurling, Hand Knurling is very likely conducted manually with some assistance, if any, from simple manual tools like Knurling knives and wheels.

Normally, manual knurl or small batch production with scrutiny over a job of intricate shape should be applied here. Although it entails greater flexibility and manually achieved crafts, this process is usually less swift and more demanding. This method is often applied when the highest level of uniqueness is needed for Knurlings. Such areas as watchmaking, jewelry, car personalization, and others.

Machining knurling

Machining knurls is an engineering manufacturing process aimed at increasing the resistance to movement of a part or improving its outlook. The process involves using a machining tool, usually a lathe, milling machine, or drilling press to carve off the surface of a workpiece to get the required shape and/or texture.

Knurling is generally used for high-precision, high-volume production, and specific shape requirements. This technique provides a higher level of automation where it mostly produces more than that achieved by hand knurling. For example, it can be utilized for gripping purposes during production of the automobiles, and machining operations, as well as improving the aesthetic value of the products.

The types of knurling texture

Straight Knurling:

Straight knurling creates straight longitudinal grooves on the surface of the workpiece. It is a kind of textured coating to increase grip and is usually apparent on handles, knobs, and hand tools.

Diamond Knurling:

On the surface of the workpiece, diamond knurling gives a pattern of ridge shapes that appear like diamonds. It is common in such a pattern to provide a good hold for it; that is why you can often see it on items like knurled thumb screws.

Crossed Knurling:

Commonly referred to as straight knurling in two directions, crossed knurling is usually done at 90 degrees apart. It is used on high-torque applications such as drill chucks and gives an even better grip.

Straight Pitch Knurling:

Straight-pitch knurling is like straight knurling, the only difference being that lines have a specific pitch. Such knurling is applied when pitch precision is needed.

Annular Knurling:

The argument here is that annular knurling results in concentric rings or circle patterns on the surface of a workpiece. This type is decorative or for show and can often be witnessed on such things as ornamental handles, jewelry etc.

Helical Knurling:

In helical knurling, the pattern is on a diagonal or spiral around the working surface. Cylindrical knurling is used in this type when there is a workpiece, with a spiral pattern it is better to grip and easily rotate the section.

Push Knurling:

Push knurling is the type of knurling in which, the tool for knurling gets pushed against he workpiece for creating a pattern. It applies to softer materials such as plastic.

Bump Knurling:

Bump knurling generates small bumps on the surface of a workpiece. For example, it is applied to improve grip and is usually observed on such things as grips of bikes.

Knurling tool and holder

The knurling tool list

  1. Knurling wheels

They are round knives for cutting and extruding surfaces, forming a knurling appearance on the latter. Such stripes appear in various designs—straight, diamond, and biased, among others.

  • Knurling rollers

They look like knurling knives but are rolling tools and most of the time used on semi-auto and auto machines.

  • Knurling dies

These instruments are applied commonly to rotating machines, where the shape is etched by pressing the piece onto a knurling die.

  • Knurling inserts

These are the common knurls that are used on today’s CNC machines. Most of these knurling tools have change-out inserts or knurled heads, which can allow fast alteration to a new knurling pattern.

  • Automatic knurling machines

Such types of machine tools are used for mass production typically coupled with a high level of automated knurling.

The knurling holder list

  1. Bump Holder

The Bump Holder is a tool suitable for engraving bumps on various work pieces. Its design is such that it will be stable enough to hold the engraver for accuracy during the work.

  • Straddle Holder

The Straddle holder is designed for holding the scribing device which can simultaneously scribe two parallel working areas. This allows more than one operation of the workpiece to be achieved simultaneously to enhance productivity.

  • Scissor Holder

It is a scissor-styled device that is meant to be used as a holder for different types of scribing instruments such as scribing knives and scribing rollers. The scriber is very versatile.

  • Swivel Holder

Additionally, a holder is a vital part known as a “Swivel holder.” This allows the scribing tool to be scribed at various angles, which proves to be vital in the peculiar considerations of scribing on the round or tapered workpieces. This feature rotates the tool according to the profile and requirements of the workpiece.

Why do you need the knurling for your machined parts?

Knurling is a surface treatment whose chief applications involve offering greater gripping and friction. This generates a concave-convex shape of the material. The shape is very beneficial in applications such as hand tools, knobs, and switches. The shape enables firm gripping thus preventing slippages.

Additionally, Knurling gives one more grip by adding feel as well as maneuverability, resulting in a greater command of steering and much-needed comfort. It is vital as far as many handheld devices and implements are concerned for ease and comfort during use.

Knurling addresses this kind of risk since knurls make surfaces rougher, thereby minimizing slipping chances, especially in slippery environments such as those that are oil-drenched or wet, thus reducing accident cases.

Knurling also adds to the looks of a part or type of machinery, giving them an enriched and smooth design. Product appeal and value are highly enhanced by incorporating it, as it’s found widely applied in automotive parts, jewelry, and watches. Briefly, Knurling plays a vital role in all these areas of production and design.

The common knurling material

Metal materials suitable for Knurling:

Aluminum: It is very knurled due to its excellent workability especially designed useful for metal products applied to be decorative and lightweight ones. It is light and it resists corrosion. However, it is less hard therefore Knurling may not endure for more than the others.

Brass: Due to their workability, corrosion resistance, and aesthetic value, brass is also another common material used in Knurling. Brass is much harder and this makes it better suited for applications where Knurling must last a long time.

Steel: Steel comes in a lot of variations, but most forms are acceptable for Knurling. in most cases, these knurls are extremely durable and strong and are suitable for tough uses.

Plastic materials suitable for Knurling:

Nylon: Nylon is known to be a hard plastic with very good abrasive properties, and thus, makes a popular Knurl material. Among these is a better performance of materials that are lightweight as well as non-conductors for these applications.

Polypropylene: Another such plastic is Polypropylene which possesses high rigidity quality and resilience against wear and tear. Mostly, it finds application with regard to the manufacture of spare parts and boxes.

Polyvinyl Chloride (PVC): Knurling is relatively cheap on PVC, a kind of plastic. it is relatively rigid and can be utilized for the production of diverse articles, such as tubes, and components, among others.

When selecting the right material for Knurling, the following key factors need to be considered: these include hardness, abrasion resistance, workability, and specific requirements for the intended use. Hardness has to be sufficient for having a bright surface, abrasion resistance ensures long-lived knurling, the working capacity guarantees the knurl plate won’t be distorted while the knurling process continues, and special properties depending on the application such as weight, electric conduct, and corrosion resistance

Considerations for knurling design

Material and texture design

The first aspect for consideration in knurling’s design is the choice of material. The effectiveness and durability of Knurling depend on its hardness and its abrasion resistance. As such, keep in mind that the hardness should be able to stand the strain and knurl for the required pattern of knurling to get a permanent knurling pattern impression. Also, the texture should be well-designed. Different parameters such as the selection of the type of texture (drilled or paralleled), spacing of the texture, and the angle and depth of the texture are based on the particular need for a suitable grip.

Craftsmanship and Security

Knurling can be achieved in different ways that include mechanical cutting, tumbling, and/or roller grinding. This particular choice must involve considering the specific material and shape necessary for the process. In addition, take necessary precautions while performing the Knurling operation in order to avoid injuries to the operator.

Surface quality, maintenance, and application requirements

Knurling can alter the finish of the work. Consequently, the final Knurling surface should be sanded or polished in order for it to attain the level of smoothness required by the surface quality appearance. Lastly, cleaning and maintenance should also be factored in to ensure that dust or other impurities are not attracted to the surface. Lastly, the design ought to be modified in reference to the special needs of the application for it to satisfy the operational requirements as well as the esthetic characteristics.

The Areas of application of knurling

Knownurling as it is known is very flexible and could perform its duties in various industry sectors. The following are some of the major manufacturing industries that can benefit from the application of Knurling:

Mechanical Engineering

Knurlings are one of the forms that are typically used in the Mechanical Engineering of the parts for parts rotation and to increase the gripping ability. It is very common, especially in the production of some components like gears, bolts, nuts, handles, etc. It also reduces the loss of rotational force on account of less friction thereby increasing the lifespan and output of mechanical machinery.

Automotive Manufacturing

For instance, Knurling is one of the most utilized manufacturing techniques of control surfaces like steering wheels, brakes, and accelerators in the automotive industry to improve drivers’ feel and maneuverability. This enhances the reliability, security, and handling ability of the car.


The user’s comfort when handling other types of equipment and tools in production processes, like hand tools, jigs, and machinery knobs is usually enhanced by knurling as well. That’s because workers can easily adapt and move around at ease thereby improving efficiency in their work.

DIY and craft sector

Knurlings are equally popular with home producers and handicraft projects. It enhances the beauty of hand tools such as handcraft and makes it easy to hold on it.

The knurling case.

Knurled cabinet knobs and knurled kitchen hardware have gained acceptance and are now among the fashionable and practical trends in home décor. These decorative pieces provide extra grip on their surfaces apart from adding a special touch to the furniture and cabinets.

Knurled door hardware has become widespread in the domain of door locks and doors. It has a special look that helps with opening and closing doors, as it adds safety too.

Knurled handles for power blocks and knurled grip sockets are required by manufacturers of industrial equipment. Knurled drive rolls along with knurled rollers offer great grip to assist in the operation as well as enhanced traction for the smoother running of mechanical parts.

Knurling of faucets and pipes for faucets and piped water is used as a non-slip design with increased operational convenience. However, knurled nuts drivers happen to be essential devices that facilitate the fixing of nuts as well as bolts no matter the variety.

Moreover, knurled thumb nuts and knurled set screws may also be employed, making it easier adjustment and fixing for their mechanical parts positions. Knurled wedding bands are now very common in the decoration industry and are used to create different textures for wedding rings in order to make them stand out.


Briefly, knurling is very important for the engineering of machinery involved in making things for design and provides extra grip, less possible slip, and a better look. It has a wide range of applications in different sectors; for instance, mechanical engineering, automotive manufacturing, general manufacturing, and do-it-yourself and crafts. Careful consideration has to be given to different knurling textures and material selection for particular requirement purposes. Knurling is one of the most useful and important engineering processes that improve the function and look of a multitude of goods, including tools and mechanical parts, home accessories, or handicrafts.

In case you wish to achieve accuracy and sophistication in machining, this is what you should go by. The latest technology and expert personnel are available in our professional CNC machining factory to meet specific needs. We handle complex knurl profiles, special designs, and any general machining you need. Call or contact us anytime through our phone numbers, website, email, and social media platforms to discuss your project and have a glimpse of what our advanced CNC machining capabilities can do to your product line. Our precision engineering will bring your ideas to life. Contact us today to get a quotation and see what difference our CNC machining will make to your firm.


On-demand CNC Machining prototyping and parts with Custom Finishes and low volume manufacturing.

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