All Metal (Inch) / Flanges (Inch) Aztech Locknut Company > Locknuts > All Metal (Inch) > Flanges (Inch) Top Lock Flange (TechPlus) Hex drive nut and washer combination Cone Top Flange The cone at the top of the nut is the receiver for the two or three impression locking elements. Center Lock Flange Reliable, very versatile and low cost Free-Spinning Flange Nut Type