one aspect of the present invention the proportion of bismuth is within the range of 35 to 65 of the proportion of lead that it replaces in a further aspect of the present invention the powder composition may be bronze powder and the bismuth may be present in an amount of up to 5 by weight the bismuth may be present as an elemental powder or may be prealloyed with another constituent of the powder composition for example where the powder composition is bronze powder the bismuth may be prealloyed either with tin as a bismuth tin alloy in powder form or with copper as a copper bismuth alloy in powder form in a further aspect of the present invention a proportion of lubricant may be included to improve further the machineability of the resulting alloy a typical lubricant is graphite which may be included in an amount of 0 1 to 0 9 by weight other lubricants are low density polyalkylenes such as that commercially available under the trade name coathylene stearic acid and zinc stearate which may be included separately or in combination in a powder metallurgy bronze powder in accordance with the present invention lead may be replaced by approximately one half of its quantity of bismuth to obtain the same degree of machineability i e in general terms 2 of bismuth could replace a 4 on the weight of bronze powder of lead investigations have established.