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Industry Terms and Definitions

Below you can find a glossary of terms related to the lumber and timber industry to help you better understand SPTP’s products and services and how they can benefit your organization. 


Shorthand version of "Glue Laminated"


To examine lumber or timbers for strength, defects, appearance, etc. according to an established set of rules


A stamp or symbol indicating the grade, quality and or intended use of a piece of lumber, plywood, or other wood product; to be recognized as "grademarked," the product must bear an official stamp issued by a grading agency and applied by a qualified grader, or it must be accompanied by a certificate attesting to the grade


A worker who examines lumber, plywood, or other wood products and assigns it a grade according to an established set of rules; the grader is usually an employee of the mill, but sometimes is employed by a grading agency which charges the mill for his services

Grading agency

An organization that provides grading rules, gradestamps and supervisory services to member producers; the agency is financed by assessing users of the service a rate based on their production

Grading rules

A set of criteria by which to judge various pieces of lumber or plywood in terms of strength, appearance, and suitability for various uses; regional grading agencies draw up rules for grading based on the voluntary product standards issued by the U.S. Bureau of Standards


A general term referring to the arrangement, appearance, and direction of wood fibers. Among the many types of grain are fine, coarse, straight, curly, open, flat, vertical, and spiral; in paper making, the predominant direction in which the fibers are aligned


A heavy set of tongs developed primarily to eliminate large tong holes in logs; used with a log loader equipped with a heel boom for loading logs onto trucks


Unseasoned; not dry, lumber