Tab washers are an additional form of lock washer that features external notches or tabs designed to hold the nut in place in relation to the connecting bolt or stud. Tabs may be bent or engage into keyways or slots in connected surfaces to provide a positive locking surface.
To fit over M12 Bolt
	
Actual Inside Diameter	13mm
Outside Diameter 		 24mm
Tab width 			12mm
Length of long tab		28mm from Centre of hole to the end
Length of short tab		15mm from Centre of hold to end
Thickness			1.0mm