The invention relates to a base body for a drilling tool, in particular to drilling/grinding tool whose front surface (14) can accommodate a cutting insert holder (2). Said invention also relates to a cutting insert holder used with said base body (1) provided with a seat for receiving a cutting insert (13, 13′, 13″). The aim of the invention is to develop a flexibly usable drilling tool whose cutting insert holder can be adjusted in a simple and accurate manner and is not expensive. For this purpose, at least one adjusting pin (4) which is connected to the base body (1) axially overlaps the cutting insert holder (2) and/or the cutting insert in such a way that a radial adjustment of the cutting insert holder (2) with respect to the base body (1) can be carried out by measuring the radial deviation (a) between the defined point of the cutting insert holder (2) or a cutting insert (3, 3′, 3″) accommodated thereby and the adjusting pin (4). In addition, a bearing surface (19) for supporting the cutting insert holder (2) on the front surface (14) of the base body (1) of the drilling tool is provided with a projection (17), preferably longitudinal, which extends outside the bearing surface (19) and is embeddable into a groove (15) on the front surface (14).