Wear on a hardened 3 mm allen key: factory new in the upper image, after 100 cycles tightening and removing stainless bolts in the lower image
<a href="//commons.wikimedia.org/wiki/User:Phiarc" title="User:Phiarc">Phiarc</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>