How are keys made?

The key is a mechanical transmission element that rotates a shaft and hub assembly. Key manufacture varies according to the type of key required, but always involves several manufacturing stages, from design to finishing. In this article, we'll take you through the general steps involved in manufacturing a key.

Drawing, rolling and shot-blasting

The first step in manufacturing a key is the shot-blasting, rolling and drawing of the raw material to give the final cross-section of the key. This step reduces the size of the raw material to the desired size of the key. At Gardette, we have invested in the know-how of cold steel processing. This equipment enables us to manufacture a wide variety of standard and special steel profiles.

Cut

Once the raw material has been prepared, the key is cut using cutting tools such as saws or form cutters. This step enables the key to be cut to the desired length and shape. At Gardette, we are equipped with circular or band saw milling machines. We also have shape-milling cutting machines, to produce form A and C-shaped keys with record productivity.

Completion

Finishing is the next stage in the manufacture of the key. This may involve drilling and tapping by milling, or simple chamfering by tank or sloping by CNC. This step creates the grooves, countersinks or other shapes the key needs to remain in position during use. At Gardette, we are equipped with flat and double grinding machines, 3- and 4-axis machining centers, traditional milling machines and 2 robotized cells for loading/unloading parts.

Tribofinishing

Tribology is the study of friction, wear and lubrication. Tribofinishing enables us to apply the principles of tribology through the wear of parts via a mixture of abrasives and passivation liquid. Although often negatively connoted, this wear is necessary to ensure that our parts meet our customers' requirements. It removes burrs from previous manufacturing processes, improves the surface finish of parts and lightly radiuses sharp edges to facilitate handling and assembly of our keys. At Gardette, we have two technologies at our disposal to carry out this key step: vibration, which involves mixing the parts with abrasives in a vibrating bowl at a defined frequency and amplitude, and centrifuging, where the parts are rotated using a rotating bottom. Although centrifugation is the most efficient process, we are limited by the geometry of the parts (deformations, part sizes, inertia due to mass, etc.).

Treatments

The key can undergo various types of treatment to improve its mechanical properties and resistance to corrosion and wear. There are 2 types of treatment: heat treatment and surface treatment. Heat treatments modify the mechanical properties of parts by altering the microstructure (e.g. quenching + tempering improves a part's mechanical strength and hardness through the formation of martensite, while maintaining a certain maximum elongation depending on the annealing time and temperature).

Surface treatments form a protective layer on steel to protect it from the environment in which it will be used (e.g. zinc plating forms a sacrificial anode on parts for a defined period of time, i.e. the zinc oxidizes instead of the iron in the steel to protect the part, forming first white rust (from the zinc) and then red rust (from the iron).

Quality

Raw materials, semi-finished and finished products are systematically inspected from the moment they enter the warehouse to the moment they are dispatched to the customer. When a batch of raw material is received, the steelmaker's certificate and batch dimensions are checked before the material is validated and entered into the ERP system. During manufacturing, parts are cross-checked by the operator, the sector manager and the quality department. All production orders are subject to a final check by the quality department before being placed in stock or released for shipment.

It is during the final inspection stage that the documents potentially required by the customer are issued (type certificate 2.1, 2.2, 3.1 according to NF EN 10204, dimensional surveys, processing certificate, FAI). We can also set up breakpoints, monitor the capability of production and measurement equipment, and draw up inspection plans to produce prototype files and complete initial samples (DVI and PPAP level 3).

Logistics and packaging

Once the key has been manufactured and inspected, it is ready for storage and/or delivery. Packaging is the process of wrapping wedges in appropriate materials (bags, cardboard, pallets, etc.) to protect, store and transport them safely throughout the supply chain. It plays a crucial role in protecting our wedges during storage and transport. At Gardette, packaging complies with standards and regulations. We can also adapt to specific customer requirements (bagging, carton and customer-specific packaging, etc.).

The logistics stage consists of planning delivery according to the needs and deadlines agreed with the customer. At Gardette, logistics encompasses several activities: inventory management, in-process order tracking, customer information, transport management and customer returns. This process must be aligned with business objectives and take account of budgetary and operational constraints. Good logistics planning helps to improve operational efficiency, minimize risk and increase customer satisfaction.

Delivery

The final stage in the manufacture of a key is delivery. The key is shipped to the customer according to the agreed terms and deadlines. At Gardette, once the key order has been prepared, it is loaded onto trucks according to the nature of the goods, the weight and/or the requirements of the order.

Delivery is a key stage, since efficient, well-managed delivery can have a positive impact on customer satisfaction, corporate image and business relations.