Bit Blocks and Sleeves
A bit block or bit toolholder or pick sleeve holder is a metal block that holds the coal mining bit and bit sleeve during work. The bit sleeve fits over the miner bit and is inserted into the hole of the bit block. As the bit block rotates with the drum, the cutting bit (also called the cutting pick) also spins inside the block to ensure even torque.
Bit sleeves provided by Yanggu offer different model numbers for customers to choose from, including 500, U170, U82A and U82B. The pick block is a forged part made from medium-carbon alloy steel through heat treatments for high strength, weldability, and extended service life.
High-strength welding wires are used to create rugged joints between the drum and the block. For installation on heavy- and medium-duty drums, the bit block, sleeve and cutting bit can rotate with respect to one another. This rotating manner allows the cutting pick to wear evenly on all sides. For extreme-duty drums, the bit sleeve is fixed to the bit block and they rotate together, while the bit can rotate inside the sleeve. Or as an alternative, the pick block, sleeve and pick can rotate with respect to one another to prevent uneven wear.
