MenuFabrication & Woodworking Glossary
A comprehensive terminology guide explaining critical concepts in material cutting, layout nesting, saw safety, and workshop calculations.
Saw Blade Kerf
The width of the cut made by a saw blade, which represents the thickness of material lost to sawdust. Standard table saw blades typically have a 1/8 inch (3.2 mm) kerf, while thin-kerf blades average 3/32 inch (2.4 mm). Kerf must be mathematically accounted for to prevent finished parts from being undersized.
Trim Cut / Clean-up Cut
A preliminary squaring cut performed along the outer perimeter of rough sheet goods (typically 1/4 inch or 6 mm) before cutting individual parts. Factory edges are rarely perfectly square and are often damaged during transit or storage. Subtracting trim cut margins from your starting stock sheet size ensures layout accuracy.
Grain Direction / Grain Orientation
The alignment and pattern of wood fibers running along the length of a board. When cutting solid wood or veneered sheet goods (like oak or maple plywood), parts must often be aligned with the grain for structural strength or visual symmetry. Non-directional sheet materials like MDF, particleboard, or sheet metals do not require grain alignment.
Edge Banding
A thin strip of veneer, PVC, or wood applied to the raw, exposed edges of plywood or MDF panels to hide the core and simulate solid lumber. When planning cuts, the thickness of the edge banding (e.g. 0.5 mm, 1 mm, or 2 mm) must be subtracted from the raw panel size if the edge tape is applied after cutting.
Rip Cut
A cut made parallel to the natural direction of the wood grain, or along the length of a sheet/board. On table saws, rip cuts are performed using the rip fence as a guide.
Crosscut
A cut made perpendicular (90°) to the natural direction of the wood grain, or across the width of a sheet/board. Typically performed using a miter gauge, crosscut sled, or miter saw.
Kickback
A dangerous safety hazard on a table saw where the workpiece binds between the rip fence and the spinning blade, pinching the blade and being propelled violently backward at the operator.
Riving Knife
A metal splitter plate mounted directly behind a table saw blade that rises and falls with the blade. It prevents the cut wood from pinching the back of the blade and causing kickback.
Board Foot (BF)
A unit of volume measurement for solid lumber, representing a piece of wood 12 inches wide, 12 inches long, and 1 inch thick (nominal). Used for purchasing rough hardwood lumber.
Alternate Top Bevel (ATB)
A saw blade tooth geometry where the tips of alternating teeth are ground at opposite angles. ATB blades slice cleanly through wood fibers, making them ideal for crosscutting solid wood and veneered plywood with minimal tearout.
Zero-Clearance Insert
A custom throat plate for a table saw or miter saw with a narrow slit cut by the saw blade itself. It supports wood fibers right up to the edge of the cut, preventing tearout and splintering on the bottom face.
Bend Deduction (BD)
In sheet metal fabrication, the amount of material subtracted from the sum of the leg lengths of a bent part to find the flat pattern layout length. It accounts for the stretching of metal during the bending process.
Nesting Density
The ratio of the area of your cut parts to the total surface area of the raw stock sheets, expressed as a percentage. A higher density indicates a more efficient nesting layout with less scrap waste.
MDF (Medium-Density Fiberboard)
An engineered wood panel product made from wood fibers combined with synthetic resin or binders, compacted under heat and pressure. It has a flat, homogeneous structure with no grain direction.
Lumber Acclimation
The process of letting wood adjust to the temperature and humidity of the workshop or destination environment before surfaced or cut, ensuring the moisture content stabilizes to prevent warping.
CNC Tabs
Small tabs of uncut material left between the routed workpiece and the scrap sheet during CNC routing, keeping the part securely anchored in place so it is not thrown by the cutting forces.
Nominal vs. Actual Dimensions
The difference between the labeled dimensions of lumber (nominal, e.g., 2x4) and its actual finished dimensions (actual, e.g., 1.5 x 3.5 inches) after drying and surfacing at the mill.
Sheet Goods
Manufactured wood panels typically sold in 4x8 foot sheets, including plywood, MDF, particleboard, and hardboard, widely used for cabinet carcasses, shelving, and paneling.
K-Factor
In sheet metal fabrication, the ratio of the neutral axis position (where no material compression or stretching occurs during a bend) to the total material thickness. The K-factor typically ranges between 0.3 and 0.5 depending on the material type (steel, aluminum) and bend radius. It is critical for calculating flat-pattern lengths.
Remnant / Offcut
The unused portion of a sheet or board left over after all parts have been cut. Unlike garbage scrap, remnants are large enough to be reusable for future projects. Saving offcuts and entering them as starting stock sheets in your next optimization run dramatically cuts down lumber costs.
Pythagorean 3-4-5 Rule
A geometric technique based on the Pythagorean theorem (a² + b² = c²) used to check if a corner is exactly 90 degrees. Measuring 3 units along one edge and 4 units along the perpendicular edge must yield a diagonal distance of exactly 5 units for the corner to be perfectly square.
Equilibrium Moisture Content (EMC)
The moisture level at which wood neither gains nor loses moisture to the surrounding air. Wood is hygroscopic, expanding and contracting seasonally. Building furniture with lumber that has not acclimated to the destination environment leads to joint failures, warping, or splitting.
Disclaimer: All workshop techniques and calculations should be performed with appropriate safety equipment. Consult tool manuals (such as your DeWalt, Bosch, or Ryobi manuals) before executing cuts.