Lock Nut / Slotted Nut / Hook Spanner Slotted Nut DIN 1804Slotted Nut for Hook wrench / Hook spanner. Size: M6x0.75~M200x3.Material: Steel C1020, C1045, A3. Stainless Steel 201, 304, 316.Surface Finish: Plain, Black Oxide, Zinc Plating. Size, thickness, style or other specifications can be designed according to your demand.