The Top Bar The top bar can be either thick ( 3/4″ ) or thin (3/8″ ). All manufactured top bars are 18-7/8″ to 19″ long and are 1-1/16″ wide. Though still usable, the variation in length is just enough to cause a bit of confusion if equipment from diffe rent manufacturers is mixed. Thin top bars are used for comb honey production and may be slotted or solid.
Obviously, thin top bars are part of a specialty frame and are not commonly seen. Thick top bars, with a wedge for attaching foundation, are the one s most commonly seen. Occasionally, a grooved thick top bar may turn up. These are used in conjunction with a grooved bottom bar and are intended to support either plastic or plastic-centered foundation. Also, hookless, crimp-wired foundation can be used with a grooved frame.
The Bottom Bar Bottom bars can be either split, two-piece, grooved, or solid. Two-piece bottom bars are probably the most common, but I canít say that itís any better than the other styles. All require the same amount of fastening. Be sure to get the appr opriate foundation for the type of bottom bar that is to be used.
The End Bar Except for length and cuts required to accept the bottom bar, the end bar is dimensionally standard. Nearly all end bars are 3/8″ thick and are scalloped half their length on both edges to allow bee movement between frames. On some, one of the unscalloped edges is tapered to a narrow edge. In the correct position within the hive, the narrow, tapered edge on one end bar should adjoin the broad, flat edge of its neighboring end bar. This serves to decrease frames being strongly stuck together wi th propolis.