This is a tiny component by micro knurling process.

As you can see from the comparison with 1 yen coin,it is as small as a fingertip and very difficult to grab.

These knurled components have a wide range of applications, including material bonding and medical instruments such as tweezers.

There are multiple methods for knurling, but this particular component is finished using grinding with a whetstone, resulting in a smooth surface finish.
The pitch accuracy is also in the micron range, ensuring excellent precision.
Although the peaks can be easily chipped or crushed if bumped, the knurling is carefully managed to ensure the peaks are well-defined and not flattened.