Quartersawn, Rift Sawn, and Flatsawn — What's the Difference?
A photo example and discussion of grain direction in sawn lumber. February 4, 2011
Question
I am not a wood expert by any means and I am just hoping to hear an objective opinion as to what I obtained for hardwood flooring is indeed rift and quarter sawn white oak. I have attached a PDF file which shows four planks stacked on top of each other, the top two of which are widely representative of my floor shipment. I would just like to know if the top two pieces of flooring (the left most two, in the third page which shows the floor face) are commonly accepted as rift and quartered oak per NOFMA standards.
Quartersawn or Flatsawn
Forum Responses
(Sawing and Drying Forum)
From contributor M:
Regardless of what the NOFMA standards may say, the two boards on the left in the face view are flat sawn, the third board from the left is rift and the far right board is quartersawn. Do not accept the flooring boards if they were sold as rift/quartered, but look like the first two in the face view. Flatsawn boards will shrink and swell in width more than rift/quarter, may cup with seasonal moisture changes and will not look or wear as well as rift/quarter.
From contributor M:
Two boards on left definitely flat sawn, third board 1/2 flat sawn with sap (would be rejected on qtd/rift job). Only board on right side is qtd/rift. Send it back. When installed and finished the appearance will not be what the customer ordered as well as movement issues previously mentioned.
From Gene Wengert, forum technical advisor:
Lumber can be sold as quarter and rift and the NHLA defines quartersawn for a wood like oak, as having the ray fleck pattern in much of the cutting used to establish the grade; this is quite useful. The NHLA does not define rift. Some times flatsawn has rings 0 to 45, rift from 45 to 75 and quarter as 75 to 90 degrees. The problem arises when a piece has mixed ring angles. Which one is used to determine f, r or q?
I do not see any flooring grade definitions of these terms for oak. In short, it is best to specify exactly what one wants to see (probably on the face and not the end) with f, r or q. I would expect that with oak, one would want to see the cathedral pattern for flatsawn, the annual rings running lengthwise without the cathedral for rift, and the heavy ray fleck pattern for quartersawn.
From contributor S:
Looking at the end view, the top two boards are flatsawn, the third from the top is a mixture of flatsawn, q-sawn, and riftsawn looking at the board from left to right. The bottom board is totally riftsawn.
Think of it this way - if you are sawing on a sawmill, either band or circular, without turning the log, only the board that contains the center of the log is rift sawn. Totally rift sawing a log can only be done practically on a rift mill. Quartersawing can be done on either a circular or band mill without too much trouble, but is more time consuming than just flatsawing the entire log. Quartersawing on a swingblade mill is easily accomplished.
From Gene Wengert, forum technical advisor:
Contributor S’s definition is the reverse of what is commonly used. The piece containing the pith is quartersawn and the adjacent pieces are also quarter sawn, as is more than perfectly 90 degrees. Rift is between q and flat, but still shows the ray fleck.
From contributor S:
Unfortunately, the common incorrect definition has been propagated for quite some time. If you Google rift sawn, you'll get some images that correctly show the difference, and some that are incorrect also. With a common sawmill, either circular or band, it is not possible to rift-saw the whole log without an attachment that will rotate the log between cuts. When sawing on either type of conventional mill, all three types of board can be produced, with the smallest percentage being rift-sawn. For the very few of us that own a rift mill, we can rift saw the entire log, because our machine is made to do that.
