Contents
Cal Poly Pomona

TERMS AND DEFINITIONS

Stock
Generic term used when referring to wood, lumber or building material.
Rough Lumber
Unlike soft woods that are pre-milled to specific dimensions, hardwoods come in random lengths and widths and are bought and sold based upon rough dimensions.  When purchasing stock from a mill, the buyer must specify the required nominal dimensions or choose a board that is appropriate for the application.  Since rough lumber has not yet been surfaced, one must always begin with oversize material.  Surfacing a board's sides removes about 1/4 inch of material from the board's thickness.  The following terms are used to indicate the thickness of a rough cut board.
4/4 material (four quarters of an inch thick) will produce a surfaced board that is 3/4" thick.
5/4 material will produce a board that is 1" thick.
6/4 material will produce a board that is 1 1/4" thick.
8/4 material will produce a board that is 1 3/4" thick.
This rule continues with 12/4, 16/4, and so on.
Surfaced Lumber
Stock with one or more faces planed flat prior to purchase.  Typically, this is the type of material you will find in a lumber yard.  The following abbreviations are used to indicate which faces of a board have been surfaced.
S & S - The board is surfaced and straight lined.
S1S - The board has been surfaced on one side.
S2S - The board has been surfaced on both sides.
S3S - The board has been surfaced on both sides and one edge.
S4S - The board has been surfaced on two sides and two edges.
Dimensions of materials
Length - The longest dimension of the material, usually in the direction of the grain.
Width - The second longest dimension of the material, usually against the direction of the grain.
Thickness - The smallest dimension of the material.
Rip Cut
A cut made parallel to (in the same direction as) the grain of the wood.  Because the grain of plywood alternates between layers, we define rip cuts as going along the length of the material, regardless of the orientation of the surface grain.
Cross Cut
A cut made perpendicular to (across or against) the grain of the wood.  Because the grain of plywood alternates between layers, we define cross cuts as going along the width of the material, regardless of the orientation of the surface grain.
Fence
A stationary reference from which stock is indexed and worked.  When making a ripping cut, use of an adjustable ripping fence ensures that the cut is square and parallel.
Miter Gauge
An adjustable, angular fence used to guide stock across the blade.  This tool is useful when making a cross cut or an angled cut.
Stops
An adjustable fixture attached to the fence which enables a cut of a particular length or width to be repeated accurately.
Kickback
When stock passed improperly through a machine is thrown out of control by the cutting blade.  A kickback implies extreme danger to the operator of the machine.

 

 

 

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