Abstract: A cylinder holder is provided for supporting a cylinder while the assembly rests on a generally horizontally oriented work surface. A radially disposed support surface provides for contact with the work surface. A tank contacting chamber is provided which has a tank contacting surface radially disposed therein which contacts a lower tank outer surface of the cylindrical tank in close proximity to a sealed end. The tank contacting chamber also has a plurality of extensions radially disposed therein to extend inward from a lower extent of the tank contacting surface. These extensions contact the sealed end of the cylindrical tank while the cylindrical tank is positioned within the tank contacting chamber. Connection means are provided to position the support surface relative to the tank contacting chamber.