PURPOSE: To prevent the generation or enlargement of a damage even in a multitude of winding and rewinding operations, by a method wherein the coating of a proper highly viscous polymeric material, such as vinyl chloride or the like, is applied on the surface of a C-section steel.

CONSTITUTION: A slide body 2, on which the cutting edge or the like of a machine tool is mounted, is transferred on a linear guide rail 1 from one place to another place in accordance with the operation of cutting, boring or the like. The tip end 5 of a linear guide rail cover 10 is connected detachably to the slide body 2 and the connecting part as well as the tip end part of the linear guide rail cover 10 are formed so as to be substantially straight tubular shape having the sections of C-shapes. The coating layer 9 of a polymeric material, such as highly viscous synthetic resin or the like, may cover the whole surface of the C-section steel 4 while the thickness of parts 9a, 9b opposing to both side ends 4a, 4b of the C-section steel 4 may be made thick comparatively while the coating of an intermediate part 9c may be made comparatively thin or nullified some times. When abnormal stresses are generated repeatingly on both side ends 4a, 4b, crack will never be generated in said parts and there may be no possibility to enlarge the crack or the like.