A base frame is used in an injection molding machine provided with a mold clamping unit having a platen, on which at least the mold clamping unit is placed and which supports the mold clamping unit. The base frame includes: a pair of main beams spaced apart from each other in a width direction of the base frame and extending side by side in a longitudinal direction of the base frame; and a platen attachment plate which is disposed on the main beams and to which the platen is attached, in which outer edge portions of the platen attachment plate in the longitudinal direction include welding points joined by welding to the main beams, and the platen attachment plate has a shape in which a length in the longitudinal direction is longer at an outer end than at an inside part in the width direction.

A mold-clamping machine includes a pressure receiving mount, a turn table mounted on the pressure receiving mount so as to be freely turnable, a movable mount placed at a position higher than the turn table, tie bars attached to and extending downwardly from the movable mount, and which pass completely through the pressure receiving mount and a traction mount. The mold-clamping machine clamps a metal mold by moving down the traction mount with reference to the pressure receiving mount. Each of the tie bars is freely movable up and down by each of first to third cylindrical guides provided at the pressure receiving mount. The second cylindrical guide and the third cylindrical guide each include a rectangular flange portion fastened to the pressure receiving mount, and respective attachment attitudes of the second cylindrical guide and the third cylindrical guide are adjustable.