BLOG

A Glimpse Inside Bedeschi’s Workshop: the Shrink Fit Method Using Liquid Nitrogen

At Bedeschi, our commitment to internal production is a strategic choice that guarantees quality, reliability, and consistency across all our projects.

Our main headquarters in Limena features an extensive internal workshop spanning 25,000 m², where we manufacture most of our key mechanical components in-house.

In the below pictures, you can observe the assembly of a series of shafts and wheels using the shrink fit method. By applying liquid nitrogen, we lower the shaft’s temperature to -196°C, which reduces its diameter by approximately 0.2 mm, allowing it to fit easily into the wheel’s hole. As the shaft returns to ambient temperature, a secure and optimal fit is achieved between the two parts due to the pressure and friction forces created at their surfaces. Essentially, the shaft and wheel become a single piece, ensuring maximum torque and axial load transmission.

We primarily use this technique to produce very heavy machines with multiple support points. A prime example is the Bucket Wheel shown here, which weighs over 1,500 tons and is supported by 48 wheels!