This diagram depicts the standard assembly of a plantation shutter tension screw. Tension screws, when tightened, draw the louver into the shutter stile. The tension which results from tightening the screw causes the louver to stay in the position that it is placed by the operator. Because the louver is attached to the Tilt Bar, and the Tilt Bar is attached to the other louvers, all louvers in the panel will remain in that position. Some tension is necessary in Plantation Shutters because the weight and location of the Tilt Bar. A  Tension Washer  or Tension Bushing is installed on the screw between the end of the louver and inside of shutter stile.  This prevents the louver from contacting the stile.  A Tension Washer is also placed under the head of the screw.  This reduces the tendency for the tension screw to "back off" during rotation of the louvers.