5/16" BSF Stainless DEEP Nut. This is a single chamfer 22 tpi double depth nut. Standard Whitworth spanner size of 0.525" across flats. 0.400" deep.
This is a single chamfer nut. It is machined back and front for a superior finish and the hexagon sides are hand finished to a semi polish. It then spends 72 hours in a polishing machine to slightly dull the sharp edges and to give them a silky feel so you do not leave cloth particles on them when cleaning the bike
You can buff it to a bright finish or sand blast it for a dull look.
These nuts are in a class of their own and not like the ones turned from hexagon bar you see elsewhere.
Two Nuts are shown for clarity, the price is for one.