Basic Requirements and Type Introduction of the Flying Shear Machine

The flying shear machine is an important device responsible for cutting in the flying cutting line. The flying shear machine can be divided into hyperbolic crank rotation and single crank rotation.

The flying shear machine is a type of shearing machine used for transverse cutting of moving rolled products. It is mainly used for cutting medium and small steel billets, thin slab billets, small section steel (bar), and hot rolled and cold rolled strip steel (including coated steel). It is also used to chop off the edges of discs cut by shearing machines (i.e. edge crushers).

Basic requirements for flying shear

As the characteristic of flying shear machine is that it can transversely cut moving rolled products, fixed length flying shear machines should ensure good cutting quality, accurate cutting length, neat cut surface, wide range of fixed length adjustment, and certain cutting speed. Therefore, the structure and performance of the flying shear must meet some basic requirements during the cutting process:

It must be able to cut moving rolled products, and the quality of the cutting section must meet the relevant national standards. That is, the flying shear machine should have a rational cutting mechanism.
It must be able to cut rolled products into predetermined lengths and can cut various fixed lengths on the same flying shear machine, with size tolerances meeting the provisions of national standards (for head cutters, it is required to accurately cut in the specified position). This requires the flying shear machine to have an accurate length adjustment mechanism.
It must meet the production requirements of the rolling mill or production line.
The speed of the flying shear must be adapted to the speed of the rolled product to ensure the quality of the rolled product and prevent equipment accidents. The use of a hydraulic roller leveler not only improves material flatness but also provides more stable support during high-speed cutting, further enhancing equipment safety and efficiency.

Types of the flying shear machine

Based on the basic requirements and working characteristics of the flying shear machine, flying shear machine generally consists of a cutting mechanism, an adjustment cutting length mechanism, a cutting edge gap adjustment mechanism, and a transmission mechanism. There are many types of flying shears used in production.

According to the part of the rolling product cut by the flying shear machine, it can be divided into head cutter and fixed length flying shear.
According to the temperature of the rolled product being cut, the flying shear can be divided into hot cutting and cold cutting.
According to the relative positions of the two blades, there are parallel blades, oblique blades, and disc blades.
According to the structure form and blade movement mode of the flying shear, there are many categories, and with the development of modern high-speed rolling mills, new types of flying shears are constantly emerging. The widely used ones are: disc flying shear machine, drum flying shear, crank rotation flying shear, swing flying shear, horizontal flying shear, etc.

How to Match the Right Flying Shear Cutting Machine to Your Production Line?

Choosing the correct flying shear cutting machine is not merely a procurement task; it is a strategic decision that impacts your entire rolling mill's efficiency. At BOYA, we categorize our approach based on two critical parameters: line speed and material specifications.

For high-speed continuous lines, such as hot-rolled strip or rebar finishing mills, the shear must synchronize perfectly with the moving workpiece. Our drum-type and rotary flying shear cutting machine solutions are engineered for these exact conditions. They utilize a advanced servo control system to maintain dynamic synchronization, ensuring precise cuts without slowing or stopping the line. This directly translates to higher throughput and reduced cycle times.

Conversely, for applications requiring extreme dimensional accuracy on thicker, high-strength materials, the mechanical characteristics of a different solution come into play. This is where understanding the distinction between a flying shear and a crank shear becomes vital. While a flying shear cuts on the fly, certain heavy-duty applications benefit from the robust, rigid structure of a crank shear, which we will discuss in the next section. By integrating our custom-developed ball cage universal joints into the drive train, we minimize torsional vibration in any flying shear cutting machine we produce, guaranteeing a longer operational life for both the shear and the upstream equipment.

Crank Shear vs. Flying Shear: A Data-Driven Approach to Equipment Selection

There is a common misconception in the market that a crank shear is simply a low-speed alternative to a flying shear. In reality, the choice between a high-speed flying shear cutting machine and a heavy-duty crank shear should be dictated by the metallurgical properties of your product and your long-term operational goals (TCO).

When the Flying Shear Prevails: If your production line primarily processes medium-to-thin gauge materials (typically < 12mm) at speeds exceeding 60 m/min, a flying shear cutting machine is the optimal choice. Its ability to cut moving stock eliminates the need for stopping and starting the line, preserving momentum and energy. BOYA's flying shears feature an intelligent length adjustment mechanism, allowing for quick changeovers between different product specifications without manual intervention.

When the Crank Shear is the Right Choice: For plate thicknesses exceeding 12mm or for materials with very high tensile strength, the lever mechanisms in some flying shears may face limitations. In these scenarios, a robust crank shear offers superior cutting force and rigidity. The parallel motion of the blades in a crank shear ensures a clean, deformation-free cut on heavy stock. However, a standard crank shear typically operates intermittently. To bridge this gap, BOYA has developed hybrid models that combine the crank shear's robust cutting action with automated feeding systems, effectively mimicking a continuous process for heavy plates.

Ultimately, the decision isn't about which type is "better," but which is better for your specific product mix. BOYA's expertise in manufacturing both types allows us to provide unbiased recommendations, ensuring that whether you need a rapid-fire flying shear cutting machine or a powerful crank shear, you receive a solution perfectly tuned to your metallurgical demands.

Flying Shear Vs Crank Shear: Which Is Better for Purchasing?

1. Material properties determine the choice:

If you need to shear high hardness/thick plates (>8mm) and have strict precision requirements (±0.1mm), choose crank shear; if the production line is mainly thin plates (<6mm) and high-speed continuous production, flying shears are better.

2. Production line speed matching:

Flying shears can dynamically synchronize high-speed production lines (100m/min+) to avoid downtime; crank shears are suitable for **low speed (<30m/min)** or intermittent production, but the shearing force is more stable.

3. Long-term cost comparison:

Flying shears have high initial investment (servo system), but low energy consumption and fast production change; crank shears have low procurement costs, but high energy consumption and high maintenance frequency, and require a comprehensive 5-year TCO evaluation.

BOYA company, starting from the development of ball cage couplings, is committed to producing core components of significant equipment in the metallurgical industry and providing various precision equipment for various production lines. It is a unique manufacturer of metallurgical equipment and the most valuable solution provider. Welcome to consult us online!

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