It is different
Waferboard (WB) and oriented strandboard (OSB) belong to the subset of reconstituted wood
panel products called flakeboards. They are structural panels made from wood wafers specially produced
from logs at the plant. When waferboard was developed in the 1950s, the wafers were not intentionally
oriented. However, by 1989 most waferboard plants were producing oriented waferboard (OWB).
Oriented strandboard originated in the early 1980s. The relatively long and narrow flakes (strands) are
blended with resin and formed into a 3- or 5-layered mat. Aligning the strands in each layer
perpendicular to adjacent layers gives OSB flexural properties superior to those of randomly oriented
waferboard. Oriented waferboard and OSB are suitable for the same markets and uses as softwood
plywood including sheathing, single-layer flooring, and underlayment in light-frame construction.
In WB production, the wafers are allowed to fall randomly to the moving screen below to form a mat of the
required thickness. In OSB production, the wafers are mechanically oriented in one direction as they fall
to the screen below. Subsequent forming heads form distinct layers in which the wafers are oriented
perpendicular to those in the previous layer. The alternating oriented layers result in a structurally
superior panel.
http://bct.nrc.umass.edu/index.php/publ ... d-plywood/