Micro-mechanical timepiece part

Micro-mechanical timepiece part (1;

• 10;
• 20;
• 100;
• 200) cut out in a silicon substrate in the form of a plate and the cut edges of which comprise portions provided to serve as contact surfaces arranged to slide against corresponding contact zones of another micro-mechanical part in a timepiece, and wherein the cut edges have a ribbed surface comprising an alternation of ribs (21a;
• 21b;
• 21c;
• 121;
• 221) and furrows (23a;
• 23b;
• 23c;
• 123;
• 223), the ribs and the furrows being straight;
• wherein the ribs and the furrows form a spaced-apart pattern, comprising a plurality of first intervals (25a;
• 25b;
• 25c;
• 125;
• 225) in which the spacing separating the ribs from each other is equal to a first distance, and at least one second interval (27a;
• 27b;
• 27c;
• 127;
• 227) in which the spacing between the ribs is equal to a second distance different from the first distance, the first distance being between 200 nm and 5 μm.