Smartbolts
I’m a mechanical engineer - smartbolts are cool but rarely used in my experience. Much more commonly used are DTI washers: <a href="https://en.m.wikipedia.org/wiki/Direct_tension_indicator" rel="nofollow">https://en.m.wikipedia.org/wiki/Direct_tension_indicator</a><p>Due to the washer style can be used with a wide range of fasteners. The most common type, in my experience, due to the ease of use, has a little bit of colored goo inside the arched cells. The goo squirts out when the specified torque is reached.<p>That being said, there are a lot of approaches to this same problem. Another common technique is breakaway bolts that are driven with a piece that snaps away when a certain torque is reached: <a href="https://youtu.be/lrCoi3gaLfU" rel="nofollow">https://youtu.be/lrCoi3gaLfU</a>