Machine part resistant to rolling friction

A machine part comprising:

• a base part formed of a titanium alloy or an aluminum alloy and having a roughened surface of Ra 0.5 .mu.m or above and PPI.sub.50 130 or above;
• and a Ni--P electrodeposit layer formed over the surface of the base part by an electroplating process using a Ni--P plating bath containing a stress relaxing agent;
• wherein the stress induced in the Ni--P electrodeposit layer is 20 kgf/mm.sup.2 or below;
• and
• wherein said Ni--P electrodeposit layer has a Vickers hardness of Hv 400 or above, a thickness in the range of 1.0 to 200 .mu.m, and a P content in the range of 0.5 to 7.0% by weight, the balance being Ni.