Please note that the content of this book primarily consists of articles
available from Wikipedia or other free sources online. A stuffing box an
assembly which is used to house a gland seal. It is used to prevent
leakage of fluid, such as water or steam, between sliding or turning
parts of machine elements. A stuffing box, or packing gland, is used
around a propeller shaft at the point it exits a boat's hull underwater.
It is the most common method for preventing water from entering the hull
while still allowing the propeller shaft to turn. In a conventional
stuffing box, the seal itself is provided by packing rings, or a square
cross-sectioned rope, made of greased flax, which is packed or wound
tightly around the propeller shaft, and compressed in place with a
threaded nut and spacer. The box may also be fitted with an opening for
periodic insertion of grease between the rings, and sometimes with a
small grease reservoir.
