השוואת שיטות

	התכווצות עץ	קשיות ינקה	Modulus of Rupture and Elasticity
תחום	ייעור	ייעור	ייעור
משפחה	Process / pipeline	Process / pipeline	Process / pipeline
שנת המקור	1950	1934	1950
הוגה השיטה	Carl Skaar	Gabriel Janka	ASTM International
סוג	moisture response test	hardness test	mechanical test
מקור מכונן	ASTM D143-19. (2019). Standard test methods for small clear specimens of timber. ASTM International.	ASTM D1037-21. (2021). Standard test methods for evaluating properties of wood-base fiber and particle panel materials. ASTM International.	ASTM D143-19. (2019). Standard test methods for small clear specimens of timber. ASTM International.
כינויים	dimensional change, anisotropic shrinkage	wood hardness, resistance to indentation	MOR, MOE, bending strength
קשורות	2	3	3
תקציר	Wood shrinkage is the dimensional change that occurs as wood loses moisture from green (freshly felled) to oven-dry condition. Wood shrinks anisotropically: tangentially (along growth rings) more than radially (from center to edge), and both more than longitudinally (along the grain). Measuring shrinkage percentages is essential for understanding wood drying behavior, predicting checking and warping, and selecting materials for applications sensitive to dimensional change (flooring, cabinetry, musical instruments).	The Janka hardness test measures wood resistance to indentation and denting by forcing a steel ball into the wood surface under standard load. Developed by Gabriel Janka in 1934, the test is a simple, nondestructive indicator of wood durability, wear resistance, and suitability for flooring, furniture, and other wear-prone applications. Janka hardness is one of the most widely used wood property metrics in wood science and commerce.	The Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) are standardized measures of wood mechanical properties determined through static bending tests. MOR quantifies the maximum bending stress wood can withstand before failure; MOE measures stiffness (resistance to bending). These are fundamental properties used for wood grading, structural design, and assessment of wood quality and species suitability for applications requiring strength or stiffness.