The Definition of Sound Cutting Explained
-By NHLA Chief Inspector, Dana Spessert
As seasoned hardwood lumber inspectors, sometimes we can forget the complexity of how the NHLA Rules are written. When I have the opportunity to work with the Inspector Training School students and other seasoned inspectors, it brings to light some of the more confusing NHLA Grading Rules. This month, I would like to explain the definition of a Sound Cutting.
As written in the 2019 version of the NHLA Rules Book on page 10, paragraph 31, under the heading of Sound Cutting, it states:
“A cutting free from rot, pith, shake and wane. Texture is not considered. It will admit sound knots, bird pecks, stain, streaks or their equivalent, season checks not materially impairing the strength of a cutting, pin, shot and spot worm holes. Other holes 1/4″ or larger are admitted but shall be limited as follows: one 1/4″ in average diameter in each cutting of less than 12 units; two 1/4″ or one 1/2″ to each 12 units and on one side only of a cutting.”
I believe the first three sentences of this definition to be mostly free of doubt as to how to interpret the meaning. Most of the confusion comes when applying the “other holes” section of the definition in the fourth sentence.
“Other holes 1/4″ or larger are admitted but shall be limited as follows: one 1/4″ in average diameter in each cutting of less than 12 units; two 1/4″ or one 1/2″ to each 12 units and on one side only of a cutting.”
Most questions center around the number of ¼” holes allowed in the Cuttings larger than 12 units. I believe this is best explained with examples.
A board has 2 Sound Cuttings; the first cutting has 11 ¾ C.U., this cutting would be allowed to have one – ¼” hole or unsound knot. The second cutting has 25 ¼ C.U., this cutting would be allowed to have four – ¼” or two – ½” holes or unsound knots. The definition states that for “each” 12 units, you are allowed two – ¼” holes or one – ½” hole, this cutting has multiples of 12 (24 +), it would allow for double the amount.
12 units up to 23.999 units – (2) ¼” or (1) ½” hole
24 units up to 35.999 units – (4) ¼” or (2) ½” holes
36 units up to 47.999 units – (6) ¼” or (3) ½” holes
The other thing to watch out for is the last part of the sentence, “and on one side only of a cutting.”, this is not an issue when looking at the backside of a Clear Face Cutting, but can become an issue when grading Sound Cutting grades, such as 2B or 3B Common.
NHLA provides a multitude of options for training and education as well as programs for yield improvement. The Industry Services team is here to help our members in any way we can. Please reach out to me to discuss ways we can help you strengthen your business and improve your company for the future.
Dana Spessert at 901-399-7551 or [email protected].