Nut: Stainless steel, European Standard No. 1.4305 (American Standard Series 303)
Not hardened or ground
On slotted spanner nuts DIN 1804-NI,
the ground surface d3 protrudes slightly and should be used
as a mating surface.
For our selection of hook spanner wrenches for use with these
components, see Section
16 - Tools, particularly
hook spanner wrenches with nose end.