|
| Half taper |
| |
Boards are sawn parallel to the centre of a log.
|
|
| Hammer bench |
| |
A wood bench as an extension of the anvil opposite the tensioner's position and supporting the rim of the saw when testing for tension; it contains a peg on a sliding panel for centering the saw while being hammered.
|
|
| Hammering |
| |
Straightening, tensioning, or flattening a saw blade manually with a hammer.
|
|
| Hand (of mill) |
| |
The hand side on which the log passes the sawyer as he faces the saw, right or left.
|
|
| Hardboard |
| |
A generic term for a panel manufactured primarily from interfelted lignocellulosic fibers (usually wood), consolidated under heat and pressure in a hot press to a density of 31 pounds per cubic foot or greater, and to which other materials may have been added during manufacture to improve certain properties.
|
|
| Hardwoods |
| |
Generally one of the botanical groups of trees that have broad leaves in contrast to the conifers or softwoods. The term has no reference to the actual hardness of wood. Also called Angiosperms or Deciduous.
|
|
| Hayrack |
| |
A type of log hauling trailer with multiple stakes to contain many small trees in the load.
|
|
| Head |
| |
The height of a column or body of fluid above a given point expressed in linear units. Head is often used to indicate gage pressure. Pressure is equal to the height times the density of the fluid.
|
|
| Headblock |
| |
That portion of a sawmill carriage on which the log rests. Each headblock consists of a base, a knee, a taper set, dogs, and a rack-and-pinion gear or some similar device for advancing the knees toward or withdrawing them from the saw line.
|
|
| Headrig |
| |
Sawing equipment used in the primary breakdown of logs.
|
|
| Headsaw |
| |
In a sawmill, the large band saw or circular saw used to saw the log into lumber.
|
|
| Heartwood |
| |
The wood extending from the pith to the sapwood, the cells of which no longer participate in the life processes of the tree. Heartwood may contain phenolic compounds, gums, resins, and other materials that usually make it darker and more decay resistant than sapwood. Heartwood is very pronounced in southern pine.
|
|
| Heat |
| |
The form of energy that has the capacity to create warmth or to increase the temperature of a substance. Any energy that is wasted or used to overcome friction is converted to heat. Heat is measured in calories or British thermal units (Btu's). One Btu is the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit.
|
|
| Heat exchanger |
| |
A device which transfers heat through a conducting wall from one fluid to another.
|
|
| Hectare (ha) |
| |
A metric unit of area, 100 metres by 100 metres (10,000 square metres); equivalent to 2.471 acres.
View: Metric / Imperial Conversion
|
|
| Heel boom |
| |
A loader with a grapple or tongs at the end of a boom or arm which forces one end of the log being loaded against the underside of the boom to steady it and raise the front end of the log.
|
|
| Helical |
| |
Spiral-shaped: in the shape of a helix or spiral.
|
|
| Hemicellulose |
| |
A celluloselike material (in wood) that is easily decomposable as by dilute acid, yielding several different simple sugars.
|
|
| Hertz (Hz) |
| |
Unit of frequency; equal to one cycle per second (cps).
|
|
| High-performance linerboard |
| |
Papers with the same strength as regular paper grades but produced at a lower weight. This process gives more compression strength per pound of fiber than conventional liner, thus reducing total fiber use.
|
|
| Hog fuel |
| |
Waste wood that is used for generation of heat and process energy; made by reducing bark to a usable size.
|
|
| Hollow grind |
| |
Grinding the saw plate on both sides so that the blade is thinner toward the eye than at the rim but leaving a hub in the center the same thickness as the rim.
|
|
| Holocellulose |
| |
The total carbohydrate fraction of wood –that is, cellulose plus hemicellulose.
|
|
| Honeycomb |
| |
A cellular separation in the interior of a wood piece, usually along the wood grain, a result of internal stress. It normally occurs during kiln drying, particularly in White or Red Oak, when too much heat is applied too rapidly.
|
|
| Honeycombing |
| |
A drying defect which occurs when tensile stresses in the core (usually a result of collapse) result in the formation of internal cavities.
|
|
| Hook |
| |
The angle at which the face of the tooth contacts the material to be cut.
|
|
| Horizontally laminated timbers |
| |
Laminated timbers designed to resist bending loads applied perpendicular to the wide faces of the laminations.
|
|
| Horsepower (hp) |
| |
The power required to lift 550 pounds one foot in one second or 33,000 pounds one foot in one minute. A horsepower is equal to 746 watts or to 42.2 British thermal units per minute.
|
|
| Hot deck |
| |
A pile of logs from which logs are hauled as soon as they are yarded.
|
|
| Husk |
| |
A term used for the parts of the sawing system supporting the arbor, saw, saw guide, and splitter, usually on a circular saw headrig; more simply, the arbor support frame.
|
|
| Hydraulic |
| |
To move or convey by fluid.
|
|
| Hydraulic balance |
| |
A condition of equal opposed hydraulic forces acting on a part in a hydraulic component.
|
|
| Hydraulic control |
| |
A control which is actuated by hydraulically induced forces.
|
|
| Hydraulics |
| |
Engineering science pertaining to liquid pressure and flow.
|
|
| Hydrodynamics |
| |
Engineering science pertaining to the energy of liquid flow and pressure.
|
|
| Hydrostatics |
| |
Engineering science pertaining to the energy of liquids at rest.
|
|
| Hygrometer |
| |
An instrument for measuring the humidity of air.
|
|
| Hygroscopic |
| |
Changes its moisture content to be in equilibrium with the atmosphere.
|
