Structural Grades

Timber grading systems have been developed to ensure quality control in the industry and help consumers buy the right timber for their needs.
Machine stress grading

Machine stress-grading uses a machine to bend each piece of timber (generally about its minor axis). 

The machine measures the stiffness of the piece and uses a loose correlation between stiffness and strength to assign a stress grade. A sorted group with a small range of E (stiffness) can produce a larger range of strength. The E value is also used to infer all of the other structural properties, including tension, compression and shear strength.

Structural grades

Higher strength grades are typically produced from the outer areas of the log.

Industrial and very low structural grades are cut from the centre. 
Prior to being cut, each log is scanned and assessed for defects and optimum cutting patterns.


Structural grades overview

Structural grades overview

F5Base grade for structural applicationsWall frames, roof trusses
MGP10Most commonly used structural grade
Wall frames, roof trusses, beams, rafters
MGP12High load applications
Wall frames, roof trusses, beams, rafters
MGP15High load applications and engineered productsWall frames, roof trusses, glue laminated beams


Data collection

Every piece of timber is machine stressed and awarded a structural grade. 
This data is recorded by Hyne Timber and kept on file for at least 1 year.

Structural properties are defined in AS1720.1 for the nominated grade.
The product requirements are defined in AS/NZS1748.1.