What are the characteristics of a key?

In this article, we'll explain what a keyhow they're made, their common applications and the advantages they offer. Whether you're an engineer, a technician or simply curious about how these small parts work, you've come to the right place! Let us guide you through the fascinating world of keys.

What is a key?

The key is an essential mechanical part for the transmission of motion in many industrial applications. It is used to rotate two parts, such as a shaft and a pulley or gear, to enable the transmission of force and motion. Different types of key exist, such as round-end keys (form A), straight-end (form B), with both a round and a straight end (form C), as well as heel and disk keys.

Material choices for manufacturing a key

The manufacturing process for wedges may vary according to the needs and specifications of each application.

Most keys are made from resistant materials such as carbon or stainless steels, but also non-ferrous materials such as brass or bronze.

The material grade and its dimensions depend on the requirements of the application, in particular :

• tree pruning
• Pulley or hub size
• The forces to be transmitted and
• The environment in which it will be used.

At Gardette Industrie, we manufacture our wedges from materials such as :

• Medium-hard steels
• Processing steels
• Stainless steels
• Exotic materials (high-alloy steels, complex stainless steels, Hastelloy / Monel / Inconel nickel alloys, etc.)
• Or any other appropriate material to meet the customer's needs.

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How are keys made?

Cold drawing

The first step in manufacturing wedges depends on the specific application and the customer's requirements.

At Gardette, we are the only manufacturer in the world with our own cold rolling, drawing and heat treatment plant. These facilities enable us to manufacture a wide variety of standard and special profiles in different materials such as steel, stainless steel, aluminum, copper and nickel alloys...

Flow rate

Once the material has been selected, it is cut to the desired length, and the keys are machined using special machines equipped with cutting tools such as saws or milling machines. At Gardette, this stage is carried out in our Cutting department. Form B keys (straight ends) are manufactured using cut-off or sawing machines. For Form A keys and all keys with complex end shapes, the two rounded ends and the length are obtained by a machining operation using special forming tools, thanks to unique technologies we have developed specifically for this purpose.

The finishing touch

At Gardette, we also offer a wide range of finishing operations. Our machinery includes numerically controlled machining centers, robotized cells, as well as a grinding workshop (flat and double-sided) to guarantee very precise tolerances or roughness imposed by specifications.
In addition, we have a long calibration island that enables us to carry out operations such as cubing material, and producing shoulders or slopes on parts.

Tribofinishing

Finally, we are also integrated with a fleet of state-of-the-art tribo-finishing machines to meet various deburring finishing needs and ensure optimum product quality.

Tribo-finishing is an important step in the manufacturing process to improve part quality and finish. It enables :

• Remove burrs
• Improve the surface finish of parts
• Radiate sharp edges, which can improve their appearance and functionality.

At Gardette, there are two technologies used for tribofinishing: vibration with vibratory bowls and centrifugation with rotating bottoms. The choice between vibration with vibratory bowls and centrifugation with rotating bottoms depends on the specifics of the parts to be treated, the desired finishing results and the requirements of the manufacturing process.

The different treatments

Once the key manufactured, it may be subjected to surface or heat treatment to improve its appearance, corrosion resistance and wear resistance.
At Gardette, we offer a complete range of surface and heat treatments.
The most common surface treatments are :

• Zinc plating
• Burnishing
• Phosphating
• Painting.

As far as heat treatment is concerned, we carry out :

• Tempering
• Income
• Annealing.

We are committed to providing tailor-made solutions to meet our customers' needs, using state-of-the-art techniques and ensuring optimum processing quality to guarantee that their requirements are met.

Quality

The final step in our process at Gardette is rigorous key inspection. During production and once the manufacturing operations have been completed, we carry out a meticulous inspection to ensure that the key meets the most stringent quality standards. Our skilled technicians use state-of-the-art, high-precision measuring tools to check dimensions, tolerances and other essential specifications, to ensure that every key that leaves our workshop conforms. Quality is a priority at Gardette.

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Where to use a key?

The keys are commonly used to transmit rotational power from a shaft to a rotating part, such as a pulley, gear or sprocket. They are used in a variety of industrial machines, such as engines, machine tools, manufacturing equipment... Keys can also be used in specific applications, such as power transmission systems for conveyors, lifting equipment, transport equipment, agricultural machinery, and so on.

At Gardette, we work with the automotive, civil and military aeronautics, nuclear, mold, engine and pump industries...

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What are the advantages of a key?

The key has many advantages over other mechanical fasteners such as clamps or welding. Here are just a few advantages:

• High torque transmission: Keys are designed to transmit high torques in mechanical assemblies. For example, a 25 mm wide key can transmit a torque of over 700 Nm, making it a robust option for applications requiring high torque transmission.

• Rigidity and stability: Keys provide a rigid, stable connection between assembled elements, which can be important in applications requiring high precision and dimensional stability.

• Durability: Keys are generally made from hardened steels or stainless steel, making them resistant to corrosion, wear and other types of damage, which can contribute to longer joint life.

• Ease of installation: Keys are relatively easy to install and replace in an assembly, with simple, well-established assembly procedures.

• Wide availability: Keys are widely used and available in many sizes, shapes and configurations, making them a common and readily available option on the market.

• Standardized design: Keys are manufactured to standardized design and manufacturing standards, making them easy to integrate into existing assemblies or new designs.

In conclusion, keys are indispensable components in mechanical systems to ensure efficient and safe power transmission. Proper use, regular monitoring and adequate maintenance are necessary to ensure their smooth operation and prevent potential failures.