Abstract: An adjustable brush is disclosed which includes a hollow cylindrical housing having a main channel coaxial with the cylindrical axis thereof and opening onto a working end of the housing. The brush further includes a plurality of filamentary bristles slideably mounted in the channel of the housing for projecting a workpiece contacting end out from the working end of the housing. The brush further includes a selectively adjustable bristle retaining mechanism mounted on the housing and mechanically engaging the plurality of bristles, for retaining the contacting end of the bristles at selected projecting positions with respect to the working end of the housing. In this manner, the contacting end of the bristles can be renewed by selectively adjusting the bristle retaining mechanism and cutting the bristles to the desired shape.