The grab bucket refers to the special tool for the crane to grab dry bulk cargo. The storage space is composed of two or more bucket-shaped jaws that can be opened and closed. When loading, the jaws are closed in the material pile, and the materials are grabbed into the storage space. When unloading, the jaws are in the pile. When it is opened in the suspended state, the material is scattered on the pile, and the opening and closing of the jaw plate are generally controlled by the steel wire rope of the hoisting mechanism of the crane. There is no heavy manual labor in the grab operation, which can achieve high loading and unloading efficiency and ensure safety. It is the main dry bulk cargo loading and unloading tool in the port. According to the type of operating cargo, it can be divided into ore grabs, coal grabs, grain grabs, timber grabs, etc.

1. Classification by shape
According to the shape, it can be divided into shell-shaped grab and orange-shaped grab. The former is composed of two complete buckets, and the latter is composed of three or more jaw plates.

2. Classification by drive mode
According to the driving mode, it can be divided into two categories: hydraulic grab and mechanical grab.

(1). The hydraulic grab itself is equipped with an opening and closing structure, which is generally driven by a hydraulic cylinder. The hydraulic grab composed of multiple jaws is also called a hydraulic claw. Hydraulic grabs are widely used in hydraulic special equipment, such as hydraulic excavators, hydraulic lifting towers, etc.
(2). The mechanical grab itself is not equipped with an opening and closing structure. It is usually driven by an external force of a rope or a connecting rod. According to the operating characteristics, it can be divided into a double-rope grab and a single-rope grab. The most commonly used is the double-rope grab.