The Collaborative International Dictionary of English v.0.48:

Flange \Flange\, v. t. [imp. & p. p. Flanged (fl[a^]njd); p.
   pr. & vb. n. Flanging (fl[a^]n"j[i^]ng).] (Mach.)
   To make a flange on; to furnish with a flange.
   [1913 Webster]