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How do we manufacture?

In order to ensure our customers a reliable and high-quality product, we have made a concerted effort to vertically integrate. This means that we do not outsource any production processes, and we take sole responsibility for the quality of our product.

This is how we manufacture screws with a
HEART OF STEEL

Drawing & Annealing

The raw material utilized at CATO is low-carbon steel wire rod, which is imported. However, we also handle other materials such as stainless steel, aluminum alloys, bronze-brass, and copper upon special request.

Initially, the wire rod undergoes a scale removal process to eliminate surface oxide. Subsequently, the material is forced through calibrated openings, reducing its diameter. The result of this operation is bright wire, known for its hardness and low ductility (not suitable for screw making).

To relieve the stresses within the material and restore its mechanical properties, we conduct the specialized heat treatment process, known as annealing, in our dedicated furnace.

To complete the wire production, the final step takes place in another machine where the material is calibrated to the exact diameter required.

Cold Forming

In the cold forming process, the calibrated wire is fed into a cold-heading machine that cuts the wire into pieces and through multiple strokes stamps the head and body of the rivet (threadless screw).

These rivets then go through a thread rolling machine whereby applying pressure and movement to the rivet, with the dies, the thread is imprinted to the rivet and the screw is formed.

To produce self-drilling screws, an intermediate step is required, which involves a pinch-pointing machine which forms the drill-type points before threading.

Heat Treatment

We perform heat treatment in-house in our continuous line, providing our product with the final properties of TOUGHNESS and HARDNESS, in compliance with international standards (ASME B18.6.3/IFI 113) and our customer’s requirements.

Our heat treatment line includes a carburizing furnace, where the parts undergo high temperatures in a controlled atmosphere, followed by rapid cooling (quenching) to harden the surface. Finally, going through the tempering furnace, where material stresses are relieved, resulting in a case hardened screw with a soft, ductile core.

Surface Finishes

The products then move onto our fully automated electroplating line, where the coating is applied—a layer providing corrosion resistance and/or a decorative finish to the pieces.

The coating is achieved through the electrodeposition of zinc ions onto the surface of the screw; followed by a chromate treatment that reinforces the protective layer and imparts the characteristic bluish-silver color (yellow, black, or green as well, depending on the requirements). As part of our commitment to the environment, our electroplating facility utilizes cyanide-free alkaline zinc baths, which has a reduced environmental impact.

We have a Wastewater Treatment Plant (WWTP) where we treat the water used in our processes, ensuring that it is recycled rather than discarded. This practice helps mitigate environmental impact by reducing water wastage and aims to provide 100% of the process’ with clean water.

Packaging

At the conclusion of the production process, we reach our packaging line, where products are packed according to customer requirements. Our packaging options include boxes containing 50, 100, 200, and 500 units, as well as bulk boxes. Screws are also packed in small bags of 2 units as needed. With our new washer assembly machine, we can now provide our customers with screws featuring elastomer washers

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