Wedge Locking Washer
Bolts stay tight even when exposed to severe vibration
I first learned about Nord-Lock washers after installing a turbocharger on my 2000 Mazda Protege. Four-cylinder engines typically run rough but the addition of a turbocharger spinning at 120,000RPM caused lots of vibration and vibration causes bolts (even those secured with conventional tightening systems, safety wire, or adhesives) to loosen and I was constantly re-torquing bolts. Then I learned about the Nord-Lock washers, installed as a pair of lock washers that has cams on one side and radial teeth on the opposite side. Nord-Lock wedge-locking products positively lock the bolt in a joint which cannot loosen due to vibration but can be un-tightened in a conventional manner by sufficient torque. Nord-Lock washers were developed by a Swedish company but now are widely available through fastener stores, Amazon and eBay. Nord-Lock washers are, as one would imagine, more expensive than conventional washers but the results — when needed — well-justify the cost (and the washers are reusable).
“The key is the difference in angles. Since the cam angle ” α ” is larger than the thread pitch ” β “, the pair of wedge lock washers expand more than the corresponding pitch of the thread.”
Nord-Lock Wedge Locking Washer (Price varies depending on size and quantity)
