Q: What is the difference between quarter-sawn, rift-sawn, and quarter and rift lumber?
A: I have not seen an answer to your question that is consistent and is widely adopted by the lumber industry. The U.S. Forest Service publications generally treat lumber as being either quarter-sawn or flat-sawn, with quarter-sawn lumber having an orientation of the annual rings to the face of the lumber of 45 to 90 degrees and flat-sawn (or plain-sawn) as 0 to 45 degrees.
The National Hardwood Lumber Association (NHLA) uses a more functional definition for quarter-sawn lumber (Para. 35 of the Rules): "...80 percent of the surface of the required cuttings in the aggregate shows the radial grain angle of 45 degrees or less with one face." (Radial grain angle of 0 to 45 degrees is the same as the annual ring angle of 45 to 90 degrees.) Note that for No. 1 Common, the required cuttings would typically be 67 percent or more of the surface area of the piece, so in essence 80 percent of 67 percent must be radial grain. There is an exception for quarter-sawn oak, sycamore and locust: "90 percent of one face of the required cuttings shall show figure."
Sometimes, this general definition of quarter-sawn is divided into two groups: quarter-sawn and rift-sawn. Quarter-sawn refers to lumber with an angle between 70 to 90 degrees (sometimes 60 to 90 degrees) and rift-sawn is lumber between 45 and 70 degrees (sometimes 45 to 60 degrees). (I have not seen a definition of rift-sawn in the NHLA Rule book however.) Therefore, when you have "quarter and rift" lumber, the seller apparently wants to make sure that you know that the grain will vary from 45 to 90 degrees, compared to just quarter-sawn, where the grain could be 45 to 90 degrees, 60 to 90 degrees, or 70 to 90 degrees.
Another name that is sometimes used for quarter-sawn lumber, especially in softwoods, is vertical grain lumber when the angle is roughly 70 to 90 degrees. I hope that any readers with a different idea about these terms will drop us a note!
Have something to say? Share your thoughts with us in the comments below.