Elongated ceiling grid member and ceiling grid assembly including a plurality of the elongated ceiling grid member

An elongated ceiling grid member having a longitudinal axis in a longitudinal direction and comprising:

• an upper portion having spaced upper portion side walls (a) extending in parallel in the longitudinal direction, (b) threaded to threadably receive and retain a first threaded member and (c) including lowermost edges extending in the longitudinal direction;
• a lower portion having spaced lower portion side walls (a) extending in the longitudinal direction, (b) configured to receive and retain a second threaded member and (c) including uppermost edges extending in the longitudinal direction;
• and
• a middle portion that (a) connects the lowermost edges of the upper portion side walls and the uppermost edges of the lower portion side walls and (b) includes a pair of middle portion side walls extending in the longitudinal direction, wherein:
• each of the pair of middle portion side walls, from top to bottom when viewed along the longitudinal axis, (a) begins at or near a different one of the lowermost edges of the upper portion side walls, (b) curves toward another of the pair of middle portion side walls to join the another of the pair of middle portion side walls and (c) curves away from the another of the pair of middle portion side walls from joinder with the another of the pair of middle portion side walls to end at or near one of the uppermost edges of the lower portion side walls;
• and
• the each of the pair of middle portion side walls is continuously curved.