SeaKing Stores › M12 A4 stainless hex full nut - EACH M12 A4 stainless hex full nut - EACH £0.40 M12 thread size. A4 stainless steel hexagon full nut. Sold individually; quantity 10 means ten loose nuts. Supplier reference: A4FNM12. Add To Cart Added! M12 thread size. A4 stainless steel hexagon full nut. Sold individually; quantity 10 means ten loose nuts. Supplier reference: A4FNM12.