To convert 5.5 millimeter to inch, multiply 5.5 by the conversion factor 0.039370. The calculation is 5.5 x 0.039370 = 0.216535 inch.

5.5 millimeter equals exactly 0.216535 inch. For practical purposes, this is often rounded to 0.2165 inch.

Objects measuring approximately 5.5 millimeter include the diameter of a standard 5mm LED (e.g., Kingbright L-53GD), the head diameter of an M3 Phillips machine screw (e.g., DIN 7985 M3 screw, approx. 5.5mm), and the width across flats for an M3 nut (e.g., DIN 934 M3 nut, 5.5mm).

Converting millimeter to inch is useful for international collaboration in engineering and manufacturing, adapting designs for regions primarily using imperial units (like the USA), and ensuring compatibility of parts and tools across different measurement systems and global supply chains.

Memory aids and shortcuts for converting 5.5 millimeter to inch include remembering that 1mm is approximately 0.04 inches, so 5.5mm is roughly 5.5 times 0.04, or 0.22 inches. You can also visualize objects like a 5mm LED or an M3 nut as a physical reference point for 5.5mm.