This nut is a bar cut 5/16-26 TPI CEI threaded nut used in many applications on various British motorcycles through 1968. Commonly used on Triumph crankcase studs and bolts.
The nut is of the bar-cut type, requiring a washer under the base of the nut. CEI threads measure 5/16″-26 TPI. Made in the UK.
The nut is used on crankcase studs, cylinder head steadies, and many other applications on virtually all pre-1968 British motorcycles.Â
The nut is recommended to be used with a flat or spring washer, as the sharp edges around the base will leave an impression on a painted part or an aluminum casting.
