Grades are listed from highest to lowest.
Maximum cuttings hardwood lumber grades.
The grade name simply designates the percentage of clear wood in the board not the overall appearance.
Then calculate the cutting area.
Grading designation depends on the number of defects in a board.
Adapted from nhla 2003.
Locate cuttings to obtain the maximum area.
The common grades are likely to be most suitable for the cabinet industry most furniture parts and flooring.
Here s a chart to help explain the grading system.
A cutting that is 5 1 2 inches wide and 4 1 3 feet long is 6 1 2x4 1 3 28 1 6 cutting units.
Board width inches clear cuttings poor face total yield.
Hardwood lumber is normally graded from the poorer quality face with a few exceptions such as 1f selects and surfaced lumber.
The maximum number of cuttings allowed depends on board size.
For complete details the grading rule book can be purchased from the national hardwood lumber association.
Summary of the nhla hardwood lumber grading rules.
Each grade of hardwood lumber is determined by the size and number of clear wood cuttings which a board will yield when cut up and used in the manufacture of a hardwood product.
The grading of sawn wood into categories as it is processed helps to determine to a large extent the value and potential use possible for each board of sawn lumber worldwide hardwood lumber producers grade their lumber assuring downstream consumers of the lumber of the lumber s quality for the intended use.
Worth noting is the fact that once re sawn the cuttings obtained from the common grades will be the same clear wood as the upper grades but in smaller shorter and or narrower cuttings.
These depend on various factors like the type of wood used and the number and types of defects if any.
Explore the use of the common grades to achieve the most value considering lumber cost and yield.
The other side of a clear face cutting may contain defects as long as they don t affect the strength of the cutting.
Hardwood grading for lumber considers the size and number of pieces or cuttings which may be yielded during the creation of a hardwood product.
The actual number is usually fewer.
Hardwoods are graded by the national hardwood lumber association.
Measure cutting width using inches and fractions and length using feet and fractions.
The grading of hardwood reflects that.
Lumber is graded based on the quality and appearance of the wood.
The grading system is based therefore on the measurable percentage of clear wood that is defect free for each of the grades.
Before we get into the different grades of lumber let s take a look at the various defects you may find in a piece of lumber.
Make sure the cuttings sizes are not below the minimum size for the trial grade.
An overview of lumber grades and wood quality.
It is based on the number and size of the clear face cuttings rectangular pieces free of defects on the graded side that could be cut from the board being graded.