Logs are cut into boards in a few different ways, which produce different characteristics and amounts of waste. This article covers the different types of wood lumber cuts for boards. If you are looking for information on slicing wood veneers, please check out our article, Wood Veneer Cuts.
Plain Sawn Lumber
Plain sawn lumber is the most common type of cut. The annular rings are generally 30 degrees or less to the face of the board; this is often referred to as tangential grain.
Plain sawn lumber yields the least waste and the widest boards.
A cathedral pattern is typically evident on the face of the board.
The diagram above shows how a log can be cut so the entire contents is plain sawn. In this case, the log is rotated 90 degrees after each cut, which helps maintain the annular ring pattern. Alternatively, the log can be sawn continuously without rotating - one board after another all the way through the log (inset graphic). This will actually produce some boards that are "quarter sawn" near the center of the log (highlighted) since the annular rings will be 90 degrees to the face of the board.
Quarter Sawn Lumber
The annular rings of a quarter sawn board are about 60-90 degrees to the face of the board; this is often referred to as radial grain. The goal is to keep the grain as close to perpendicular (90 degrees) to the face of the board as possible to maintain dimensional stability.
Quarter sawn lumber yields more waste and narrower boards than plain sawn. Therefore, quarter sawn lumber is more expensive
A narrow grain pattern is typically evident on the face of the board. Flecks (also known as figure) are generally evident in quarter sawn red oak and white oak, but can also be seen in other species.
The diagram above shows two different methods of cutting quarter sawn boards, which are highlighted. The remaining boards that aren't highlighted are considered rift sawn boards since the annular rings are closer to 45 degrees.
Rift Sawn Lumber
The annular rings or a rift sawn board are about 30-60 degrees to the face of the board, but 45 degrees is the most optimum. Similar to quarter sawn lumber, rift sawn lumber is also referred to as radial grain.
The diagram above highlights the boards that are considered rift sawn. Since there are very few boards that meet the requirement of 45-degree grain, rift sawn lumber is the most expensive cut.
A narrow and very straight grain pattern is visible on the face of the board. Rift sawn lumber is usually used with oak to avoid the flecks that are common in the species.
A Note About Our Diagrams and Cutting Methods
We have received a lot of feedback about our diagrams above and we have had different versions of those diagrams at various times. There are a lot of diagrams on the internet that show different cutting patterns than we show. However, we believe our diagrams are accurate. We have done a significant amount of research and have had conversations with various lumber organizations and associations. The conclusion we have reached is that there are many different ways to cut a log into boards and different mills use different methods. Identifying a board as plain sawn, quarter sawn, or rift sawn has to do with the angle of the grain relative to the face of the board and the amount of fleck or figure visible on the face. The method of cutting the log into boards is not the important factor.
Sources
The AWI Woodworking Standards provides a more detailed discussion about the various types of wood lumber cuts.
