Rail of a machine apparatus with a traveling carriage

A rail of a machining apparatus having a traveling carriage on which a machining unit is mounted for performing a desired work on a workpiece, comprising:

• rack members each rack member of which has threaded holes at predetermined positions on one surface of each rack member;
• and
• rail members each rail member of which has a running surface formed on a head portion of each rack member with which running surface a traveling roller of the traveling carriage is in contact, guide surfaces formed on both sides of the running surface with which guide surfaces guide rollers of the traveling carriage are in contact, and an attachment surface formed below the guide surfaces for attaching each rack member, elongated holes being formed on the attachment surface at positions corresponding to those of the threaded holes,
• wherein the rail members are connected at a rail member connecting portion in series such that running surfaces of adjacent rail members are in contact with each other,
• wherein the rack members are arranged in series on the attachment surface such that an interval between teeth of adjacent rack members at a rack member opposing portion at which end portions of the adjacent rack members are opposed to each other is the same as a predetermined tooth pitch of the rack members, and
• wherein the rack members are attached to the attachment surface by bolts which are inserted through the elongated holes and which are screwed into the threaded holes.