DescriptionHexagon Socket Nut Screw Rivet Locking ScrewMaterial: 304 Stainless SteelInternal Diameter: M3 M4 M5 M6 M8 M10Outside Diameter of cylinder: 4/5/6/8/10/13mmLength: 4~120mmSize: Thread inside diameter (M/d) x Cylinder Length (L) x Cylinder Outer diameter (d1)(Head thickness (k)/ screw outer diameter (dk) will range through 0.1~0.2mm due to size)For bulk purchase, you possibly can contact the seller to get the final quotation.