Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Softwood Lumber - Grading

Rough lumber, surfaced lumber (dressed), worked lumber, shop and factory lumber and yard lumber.

Rough Lumber

Sawn, trimmed and edged lumber. The faces are rough with saw marks.

Surfaced Lumber

Rough lumber smoothed by surfacing machines. Subcategories based on the number of sides and edges that have been smoothed.

s4s wood lumber

  • S1S - Surfaced on 1 Sides
  • S2S - Surfaced on 2 Sides
  • S3S - Surfaced on 3 Sides
  • S4S - Surfaced on 4 Sides


  • S1E - Surfaced 1 Edge
  • S2E - Surfaced 2 Edges


  • S1S1E - Surfaced 1 Side and 1 Edge
  • S1S2E - Surfaced 1 Side and 2 Edges


Note that S4S lumber planed and surfaced all four sides will be noticeably less than in its nominal dimension.

Worked Lumber

Surfaced lumber that has been matched and  patterned.

Shop and Factory Lumber

Millwork lumber - used for molding, door jambs and windows frames.

Structural Lumber or Yard Lumber

Yard lumber used for house framing, sheathing, concrete forms.

Yard lumber or structural softwood lumber is subdivided in

  • Boards -  no more than 1 inch thick and 4-12 inches wide
  • Planks - more than 1 inch thick and more than 6 inches wide
  • Timbers - width and thickness greater than 5 inches

Related Topics

  • Miscellaneous

    Engineering related topics like Beaufort Wind Scale, CE-marking, drawing standards and more.

Related Documents


Search is the most efficient way to navigate the Engineering ToolBox.

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

We use a third-party to provide monetization technologies for our site. You can review their privacy and cookie policy here.

You can change your privacy settings by clicking the following button: .


This page can be cited as

  • The Engineering ToolBox (2009). Softwood Lumber - Grading. [online] Available at: [Accessed Day Month Year].

Modify the access date according your visit.

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter