What does quartersawn mean?

Since we launched our new line of Quartersawn White Oak in last year, we received a lot of questions about quartersawn. What does it mean? How is it different from our other products? So, we will try to explain the main differences between the various lumber sawing methods. We need to go down to the lumber sawing methods because it has an impact on the look of the hardwood floor at the end of the process.

There are roughly 3 ways to saw a wood log: plain sawing, quarter sawing and rift sawing.

Plain sawing or flat sawing (also called tangential cut) is the most common sawing method. This method is the simplest way to cut rectangular-profiled boards out of a round log. In plain sawing, the wood is sawn tangentially to the annual growth rings so that the rings form an angle of less than 45° in relation to the board surface. On a wood floor, this cut is easily recognizable by its cathedral arches. 

Plain Sawn description

Image credit: The Workshop Companion


Quarter sawing gets its name from the fact that the log is first quartered lengthwise, resulting in wedges with a right angle ending at approximately the center of the original log. Each quarter is then cut separately by tipping it up on its point and sawing boards successively along the axis. That results in boards with the annual rings mostly perpendicular to the faces. Quarter sawing yields boards with straight grain lines, greater stability than flatsawn wood.  Some will have a distinctive ray and fleck figure and will be known as quarter sawn others will not have the fleck figures and will be called rift sawn.  The quarter sawn boards come from the boards cut from the center of the logs where the grain angle is between 60 and 90 degrees.  The fleck is caused by the medullary rays that become apparent.  The rift sawn boards come from the boards cut from the outside of the log and where the grain angle of less than 60 degrees.  These will not show the medullary rays and will be referred to as rift sawn.

 Modern Vs Traditional quartersawing

Image credit: Brownlee Lumber

Quarter sawing is sometimes confused with the much less common "rift sawing." In quartersawn wood, only the center board of the quarter-log is cut with the growth rings truly perpendicular to the surface of the board. The smaller boards cut from either side have grain increasingly skewed. Riftsawn wood has every board cut along a radius of the original log, so each board has a perpendicular grain, with the growth rings oriented at right angles to the surface of the board. At these angles, the medullary rays are not apparent and there is not fleck visible in the boards. However, since this produces a great deal of waste (in the form of wedge-shaped scraps from between the boards) rift-sawing is very seldom used. Quartersawn wood is thus seen as an acceptable compromise between  flatsawn wood  and the expensively-wasteful riftsawn wood.

 Riftsawn schematic using a common technique

Image Credit: Wikipedia

The process indicated in the USA and Canada  as "quarter sawing" yields a few boards that are quartersawn, but mostly riftsawn boards. For its quartersawn products, Preverco uses lumber cut using the modern quartersawing method and is also refered as true Quartersawn resulting in a mix of quartersawn and riftsawn boards.

 flat, quarter vs riftsawn boards

The following video visually explains the differences between the main sawing methods and their impact on the final boards.

Video credit: The Frank Miller Lumber Company

 

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