undergo limited reciprocation the beatpiece 5 transfers impacts from the ram to a tool or bit 34 mounted within a forward tool holder portion of the spindle by a tool holder arrangement 36 for example an sds type tool holder the tool or bit 34 is releasably locked within the tool holder portion of the spindle so as to be able to reciprocate within the tool holder portion of the spindle by a limited amount in fig1 the ram and beatpiece are shown in their idle mode position in the upper half of the spindle 4 and in their operating position in the lower half of the spindle the spindle 4 which may be rotatingly mounted within the hammer housing 10 15 can be rotatingly driven by the intermediate shaft 6 as described below thus as well as or instead of reciprocating the tool or bit 34 can be rotatingly driven because it is non rotatably mounted within the spindle 4 by the tool holder arrangement 36 thus the hammer may have three modes a drilling only mode in which no hammering occurs and the spindle is rotatingly driven a hammer drilling mode in which hammering occurs and the spindle is rotatingly driven and a chisel or hammer only mode in which hammering occurs but there is no rotary drive to the spindle and in which the spindle is generally locked against rotation the intermediate shaft 6 is formed at its forward end with a pinion 38 which is selectively engageable with a spindle drive gear 39 a mode change.