เปรียบเทียบวิธี

	การหดตัวของไม้	ความแข็งของจันกา
สาขาวิชา	วนศาสตร์	วนศาสตร์
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1950	1934
ผู้ริเริ่ม	Carl Skaar	Gabriel Janka
ประเภท	moisture response test	hardness test
แหล่งต้นตำรับ	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.
ชื่อเรียกอื่น	dimensional change, anisotropic shrinkage	wood hardness, resistance to indentation
ที่เกี่ยวข้อง	2	3
สรุป	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.