H20 beam: maximum length cm: 180 /245 /290 /330 /360 /390 /490 /590cm, live load (bending stiffness): max 500kn /m2, material: made of high-grade solid sawn pine lumber and pine plywood, lvl pine, plywood, glude: muf warterproof glue, color: yellow, overall beam depth h: within 1 mm, flange width and depth: within 1 mm, web thickness: within 0, 5 mm, maximum moisture content by the time of assembly is 18% for the timber flanges and 10% for the web boards.