V4A steel is an obsolete term variant for the austenitic stainless steels of resistance class II, in accordance with the general building authority approval of Z-30.3-6 from DIBT Berlin.
The market generally understands this to mean the materials 1.4401, 1.4404, 1.4571, whereby the designation originates from old Krupp material lists, where the 1.4404 was designated e.g. as V4A Supra NK and the 1.4571 as V4A Extra.