A method of reinforcing a volume of rock by pre-bolting, said method comprising: providing a top hammer drilling machine (1, 6) for said rock volume, said top hammer drilling machine being configured for automatic feed of and drilling with a plurality of drilling modules (2, 3), initially loading the top hammer drilling machine (1, 6) with at least one of said plurality of drilling modules (2, 3), said at least one drilling module being provided with a drilling crown, automatically feeding sequentially and drilling said drilling crown and at least two drilling modules of said plurality of drilling modules (2, 3) into a resulting drill hole in the rock volume by means of the top hammer drilling machine (1, 6), fixating the drilling crown and said plurality of drilling modules (2, 3) in the drilling hole by injecting a fixation substance in the drilling hole, wherein said plurality of drilling modules (2, 3) have a maximum outer diameter of 50 mm - 60 mm and wherein the drilling crown has a maximum outer diameter of 5 mm - 16 mm larger than the maximum outer diameter of said plurality of drilling modules (2, 3), the method further comprising the step of joining said plurality of drilling modules (2, 3) by means of threadings, wherein at least one drilling module (2, 3) included in said plurality of drilling modules (2, 3) has at least a first impact surface formed at an outer end of a thread of said threadings, and a second impact surface formed by a seat at an inner end of said thread, wherein the first and second impact surface (4a, 4b) interact with respective impact surfaces of an adjacent drilling module (2, 3) included in said plurality of drilling modules (2, 3). providing a top hammer drilling machine (1, 6) for said rock volume, said top hammer drilling machine being configured for automatic feed of and drilling with a plurality of drilling modules (2, 3), initially loading the top hammer drilling machine (1, 6) with at least one of said plurality of drilling modules (2, 3), said at least one drilling module being provided with a drilling crown, automatically feeding sequentially and drilling said drilling crown and at least two drilling modules of said plurality of drilling modules (2, 3) into a resulting drill hole in the rock volume by means of the top hammer drilling machine (1, 6), fixating the drilling crown and said plurality of drilling modules (2, 3) in the drilling hole by injecting a fixation substance in the drilling hole, wherein said plurality of drilling modules (2, 3) have a maximum outer diameter of 50 mm - 60 mm and wherein the drilling crown has a maximum outer diameter of 5 mm - 16 mm larger than the maximum outer diameter of said plurality of drilling modules (2, 3), the method further comprising the step of joining said plurality of drilling modules (2, 3) by means of threadings, wherein at least one drilling module (2, 3) included in said plurality of drilling modules (2, 3) has at least a first impact surface formed at an outer end of a thread of said threadings, and a second impact surface formed by a seat at an inner end of said thread, wherein the first and second impact surface (4a, 4b) interact with respective impact surfaces of an adjacent drilling module (2, 3) included in said plurality of drilling modules (2, 3).