Reinforced cylindrical door lock set

A cylindrical door lock set, comprising:

• an outer knob supporting plate having a central hole, an outer side, and an inner side provided with a pair of posts on two sides of said central hole, said posts being hollow and being threaded internally;
• an outer door knob connected to said outer side of said outer knob supporting plate;
• a turning mechanism supported on said inner side of said outer knob supporting plate and provided with a turn shaft;
• an annular mounting plate secured on said inner side of said outer knob supporting plate and formed with a pair of mounting shafts and a central hole to permit said turn shaft of said turning mechanism to extend therethrough;
• a latch unit formed with a shaft engaging hole to permit said turn shaft to extend therethrough, and two side holes disposed on two sides of said shaft engaging hole in a lengthwise direction of said latch unit to receive respectively said mounting shafts, said latch unit being disposed between said posts;
• an inner knob supporting plate having an outer side and being formed with a central hole and a pair of holes which are aligned with said posts;
• an inner door knob connected to said outer side of said inner knob supporting plate in said central hole, said inner door Knob engaging one end of said turn shaft;
• and
• a pair of bolts respectively passing through said holes of said inner knob supporting plate and respectively engaging said posts.