No You Can Get It Right The First Time
This world is getting so techno-advanced, now even the lowly bolt is getting into the act. Behold the Smartbolt, fitted with a tiny indicator disk on top that shows you just how tight it is. There’s nothing electronic about it – it’s a visual tension indicator that starts out red and turns more black as you tighten it. There’s a more-precise version that goes from yellow to green when 90% tight, turning black at 100%.