A measurement artifact that commonly occurs during the measurement of vibration on percussive and impact tools is known as a ‘dc shift’. The effect of this is to artificially inflate the measured vibration magnitude, thus indicating an erroneous measurement. The presence of dc shifts can usually be determined by inspection of both the time history and the frequency content of the vibration signal. Although the normal precautions were taken during the vibration measurements (such as the use of mechanical filters), 13 examples of dc shifts were measured on 7 impact-type tools. The data contaminated by dc shifts measured on the tools have been analysed using high-pass filters ranging from 1 Hz to 20 Hz. Power spectral densities have been calculated for the dc-shift contaminated time histories. The corresponding vibration magnitudes have shown that the high-pass frequency that should be used depends on the main frequencies of operation of the tool. Displacements corresponding to the artificially inflated low-frequency component for some of the tools have shown values as high as 214 mm for riveting operations.