A flange is a protruded ridge, lip or rim, either external or internal, that serves to increase strength ; for easy attachment/transfer of contact force with another object ; or for stabilizing and guiding the movements of a machine or its parts. Flanges are often attached using bolts in the pattern of a bolt circle.

An I-beam is any of various structural members with an I or H-shaped cross-section. Technical terms for similar items include H-beam, universal column (UC), w-beam, universal beam (UB), rolled steel joist (RSJ), or double-T. I-beams are typically made of structural steel and serve a wide variety of construction uses.