ROCK BOLT

PROBLEM TO BE SOLVED: To easily form a knot shape, prevent bonding in a semihardened state of fixing material from separating, and insure adhesion after completing hardening, by alternately forming sections of coarse pitch and sections of dense pitch on a rock bolt by rolling. SOLUTION: The tip TIP of a rock bolt RB is sharpened, or a sharpened bolt cap BCP is fitted thereto. Coarse sections CPI of knot pitch P1 of the length Lc of about 1 m, and dense sections PPI of pitch P2 of the length Lp of about 10-20 cm re alternately rolled to form the rock bolt RB. Hereby, the knot shape is easily formed by rolling, by the coarse section CPI of pitch P1, bonding in a semi-hardened state of fixing material is prevented from separating, and by the dense section PPI of pitch P2, adhesion with the fixing material after completing hardening can be insured. Further, if necessary, a nut is threadedly engaged with the dense section PPI of pitch P2, and the rock bolt RB can be fixed to the natural ground through a washer.