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A monoblock stopper rod, also known as a monoblock stopper or simply a stopper rod, is a refractory device used in steelmaking to control the flow of molten steel from the ladle to the tundish during continuous casting processes. It is an important component in the stopper system, which regulates the steel flow and enables precise control of the casting process. Here's what you need to know about monoblock stopper rods:

  • Design and construction: Monoblock stopper rods are typically made from high-quality refractory materials, such as alumina, magnesia, or zirconia, depending on the specific application requirements. They are designed as a single-piece structure, hence the term "monoblock," which ensures strength and integrity during operation.

  • Function: The primary function of a monoblock stopper rod is to control the flow of molten steel from the ladle into the tundish during continuous casting. It acts as a movable plug that can be raised or lowered to open or close the flow passage, thereby regulating the steel flow rate.

  • Flow control mechanism: Monoblock stopper rods are equipped with a control mechanism, such as a pneumatically or hydraulically operated cylinder, that allows for precise adjustment of the stopper position. This mechanism enables operators to control the steel flow according to the casting requirements.

  • Refractory properties: Monoblock stopper rods are designed to withstand the high temperatures and thermal cycling encountered in the steelmaking process. They exhibit excellent refractory properties, including high-temperature resistance, thermal shock resistance, and resistance to erosion from the flowing molten steel.

  • Wear resistance: Monoblock stopper rods are subject to wear and erosion due to the continuous flow of molten steel. They are engineered to have good wear resistance, extending their service life and reducing the need for frequent replacements.

  • Gas tightness: Monoblock stopper rods should provide a gas-tight seal to prevent the ingress of air or gases into the steel stream during casting. This ensures the quality and cleanliness of the final steel product.

  • Installation and maintenance: Monoblock stopper rods are installed and maintained by skilled operators. Proper installation, alignment, and periodic inspections are essential to ensure the effective functioning of the stopper system and prevent issues such as leakage or excessive wear.

  • Size and customization: Monoblock stopper rods are available in various sizes to accommodate different ladle and tundish designs. They can also be customized to meet specific requirements, such as flow capacity, refractory material composition, or control mechanism preferences.

Monoblock stopper rods play a critical role in the continuous casting process, enabling precise control of the steel flow from the ladle to the tundish. Their high-temperature resistance, wear resistance, and gas tightness contribute to the efficiency, quality, and reliability of steel production.


Buy good quality low cost Monoblock Stopper Rods made of alumina-carbon type and magnesia-carbon type to suit for individual castling conditions. A broad range of designs are available for stopper head or slag line, raliable and satisfactory performances have been achieved in decades of operations worldwide.


Item Body Head
Al2O3 %≥45.0≥55.0 ≥60.0≥75.0
MgO %  ≥60.0≥12.0 
C+SiC %≥20.0≥15.0≤15.0≥10.0≥10.0
Bulk Density  g/cm3≥2.36≥2.44≥2.45≥2.70≥2.70
Apparent Porosity %≤19.0≤19.0≤18.0≤18.0≤17.0
Cold Crushing Strength   Mpa≥20.0≥22.0≥15.0≥20.0≥20.0
Modulus of Rupture   Mpa≥4.0≥5.0≥4.0≥5.0≥6.0

Monoblock Stopper Rod

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