Lumber Grades Explained at North Castle Hardwoods

Posted by Josh Kou on

Lumber Grades Explained at North Castle Hardwoods

North Castle Hardwoods Grading & Quality

At North Castle, we have worked carefully for 30 years to develop custom grades. These are designed to give furniture makers, fine woodworkers and crafters the best quality and yield from our lumber.

Our material is of unique quality that is consistently a few notches higher than the national standards for production. We have organized our quality into two easily understandable grades for woodcrafters, so you know exactly what to expect when ordering from North Castle Hardwoods. We also offer upgraded dimensioned wood products. 

Our Proprietary Lumber Grading Chart


North Castle Hardwoods B-Grade Lumber

Our B-Grade is our standard premium grade. Cut from pre-sorted logs, this standard grade offers “better than select and better” quality in a number of important areas for woodworkers and crafters. When purchasing this grade, you can expect to see a clear board on one face with a clean appearance and possible natural character on the reverse face.


Key features of B Grade:

  • Clear on one face (better face)
  • Minimal to no sap on clear face
  • Clean appearance with some possible natural character on reverse face
  • Limited sap on reverse face (if any)
  • No visible surface-checking or end-checking

North Castle Hardwoods A-Grade Lumber

Our A-Grade is our fine quality grade which is a step above our B-Grade. Sorted out from our standard premium stock, this grade is designed to offer exceptional quality for fine wood crafting and furniture making. Perfectly clear on one face with minimal character on the reverse, this grade is particularly suited to creating an even and consistent appearance for your entire project where both faces of the wood will be visible and where color consistency is important.


Key Features of A-Grade: 

  • Perfectly clear on one face
  • Minimal to no sap on clear face
  • Near clear on reverse face with minimal character
  • Minimal sap on reverse face (if any)
  • No visible surface-checking or end-checking

Dimensioned Lumber (Dimensional Lumber)

Our dimensional lumber comes from boards set aside during our sorting process.  Boards that doesn’t make our other standard grades are cut to remove defects. They are surfaced and upgraded to premium S4S lumber, ready to use in any woodworking projects.


Dimensional Lumber grade features:

  • S4S lumber (surfaced/sanded on all sides)
  • Precision machined to a tight tolerance in all dimensions
  • No wane (all sides are parallel)
  • Perfectly clear on one face
  • Sap-free on clear face (or heart-free in white woods)
  • Near clear on reverse face with minimal character
  • Minimal to no sap on reverse face (or heartwood in white woods)


North Castle Hardwoods Dimensional Products and Packaging Specifications

Dimensional Lumber Tolerances


We sand our dimension pieces on precision wide belt sander to a very tight thickness specifications.


Both edges are finished parallel, straight-line ripped on a dedicated precision glue-line rip saw. Widths are rounded down to the nearest 1/2” and measured in 1/2" increment from 2.5” to 6.5”. This means that 5” dimension board is finished at anywhere between 5”less 1/32” to 5-31/32” (5-1/2” less 1/32”), etc. We leave the extra width to give you the maximum advantage. If you would like us to finish the pcs at any specific width, please specify and we will edge them to your requirement.


You will have two clean ends. There will be an overlength of 1/4” to 2”. If you require any specific length, we can trim the piece for you, in which case the original length of the board prior to trimming will be used for measurement. 

Thickness: (+/-) 1/64”

Final dimension after sanding

Width: (-) 1/32”; (+)1/2” max

Final dimension after precision straight line rip 2 edges

Length: (-) 0; (+) 0.25” ~ 2.0”

Final dimension after cross-cut with a 16” finish sawblade


Quality Specifications

Sapwood/heartwood Content

Dark wood: Walnut. Cherry, Red Oak, White Oak have minimum 95% heartwood on one face. Walnut is always steamed to provide maximum color stability.

Maple (white wood) dimension product, on the other hand, has minimum 95% sap on one side and very white on reverse face as well.

White Ash is not color sorted, but generally very white. Heartwood in this species is generally light brown and we do not include dark brown or gray in the heartwood.  We make sure the color of sapwood and heartwood blend very well.

Clarity: generally clear both faces and both edges. The reverse face may allow small natural character, if any. Ends are defect-free. So, you are getting 100% usable wood that’s precision machined and color inspected.


Environmental Concerns

All our dimension products are carefully kiln dried and precision machined. After final machining, they are kept in climate-controlled storage and shielded from humidity variation and other elements that may be harmful to the wood, waiting for final packaging and shipment.



Our packaging reflects how much we care about protecting your dimension product you order from us. For protection from shocks and rough package handling, we first wrap them in foam sheets. We then insert them in a moisture resistant poly tube and seal it air-tight to prevent them from natural movement of wood caused by shrinkage and expansion. The wood you receive will be flat and true to dimension without showing significant cupping or warpage.  The package will leave our warehouse perfectly flat.

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