A timepiece component for a timepiece movement and notably a pivot arbor of a regulating member of a mechanical timepiece movement, made of an alloy containing by weight: between 25% and 55% of palladium, between 25% and 55% of silver, between 10% and 30% of copper, between 0.5% and 5% of zinc, gold and platinum with a total percentage of these two elements comprised between 15% and 25%, between 0% and 1% of one or more elements chosen from among boron and nickel, between 0% and 3% of one or more elements chosen from among rhenium and ruthenium, no more than 0.1% of one or more elements chosen from among iridium, osmium and rhodium, and no more than 0.2% of other impurities, the respective quantities of the components being such that, added together, they do not exceed 100%.