Fastener - Washer - Nord-lock Washer Bolt Securing System - M12

Special halved and toothed 12mm Zinc washer.

Sold individually

Inner ?ò 13mm
Outer ?ò 19.5mm
Thickness 2.5mm

"A unique bolt securing system using tension instead of friction. When the bolt and/or nut is tightened, the teeth grip and seat the mating surface. The NORD-LOCK washers are locked in place, allowing movement only across the face of the cams. Any loosening movement of the bolt/nut is blocked by the wedge effect
"The NORD-LOCK bolt securing system uses geometry to safely lock bolted joints in the most critical applications.
This unique wedge-locking system offers the following advantages:

Maximum safety
Resists loosening caused by vibration and dynamic loads
Ease of assembly and disassembly
Locking function is not affected by lubrication
Positive locking at low and high preload levels
Controllable preload
Same temperature characteristics as standard bolt/nut
Reusable"

The science behind the system, See diagram pictured below,

"Tension makes the bolt self-locking

The key is the difference in angles. Since the cam angle " Œ± " is larger than the thread pitch " Œ? ", the pair of washers expand more than the corresponding pitch of the thread. NORD-LOCK washers positively lock the fastener in a joint which is subjected to extreme vibration or dynamic loads."