The bristle block can be replaced by removing one screw from the grill brush. The stainless bristles are really thick which helps brush clean much better than other brushes. This also helps to keep bristles from breaking down and flattening out. The block that the bristles are set in is 1/2 inch thick. This helps to better set the bristles so they won’t pull out of block. You will get stainless bristles in the block.