PURPOSE: In MC machine tool, to improve the collision rate of all balls or the load capacity or service life by loading between the rolling faces of a slide table and raceway table through load balls rollable in grooves.

CONSTITUTION: A straight slide bearing B is formed to have C-shaped cross- section and constructed with a slide table 1 having a recess 6 in the lower face, a pair of said covers 2 made of hard resin, ball holder 3, many balls 4 and a raceway table 5. The slide table 1 is formed with approximately arched rolling faces 8a, 8b inclining in logitudinal direction by 45° and a ball clearance hole 9 in the inner face of both sleeve sections 7a, 7b. The raceway table 5 is formed with a notch 14 at one shoulder section and a groove 14 in the other side wall while approximately arched rolling faces 16a, 16b are formed with angle of 45° to face with the rolling faces 8a, 8b thus to load between rolling faces through the ball 4. Consequently each ball will deform resiliently to contact against the rolling face with wide contact width resulting in improvement of collision rate of all balls.