Flanged railway wheel. A flange is an external or internal ridge, or rim (lip), for strength, as the flange of an iron beam such as an I-beam or a T-beam; or for attachment to another object, as the flange on the end of a pipe, steam cylinder, etc., or on the lens mount of a camera; or for a flange of a rail car or tram wheel.
noun, plural subtleties. 1. the state or quality of being subtle. 2. delicacy or nicety of character or meaning. 3. acuteness or penetration of mind; delicacy of discrimination. 4. a fine-drawn distinction; refinement of reasoning: the subtleties of logic.
1 A subtle or slight degree of difference, as in meaning, feeling, or tone; a gradation.  Expression or appreciation of subtle shades of meaning, feeling, or tone: a rich artistic performance, full of nuance.