A study on the mechanical properties of Korean red pine (Geumgangsong, Pinus densiflora forma erecta Uyeki)

We investigated the mechanical properties of Korean red pine (Geumgangsong, Pinus densiflora forma erecta Uyeki) of Uljin province in Korea as a basic research to investigated the material properties. Compressive strength of Korean red pine was 36.2 N/mm², which was slightly lower than the pine (Pinus densiflora S. et Z.) in Korea. The compressive strength of Korean red pine showed the maximum value at a distance of 60 mm from the pith. Bending strength of Korean red pine was 76.5 N/mm², which was slightly higher than the pine (Pinus densiflora S. et. Z.) and nut pine (Pinus koraiensis) in Korea. Similar to the compressive strength, bending strength of Korean red pine showed the maximum value at a distance of 60 mm from the pith. On the other hand, the shearing strength showed the maximum value at part of including the pith. This result does not coincide with the results of compressive and bending strength, in consideration of the specific gravity, which is consistent. Surface hardness of Korean red pine was 43.7 N/mm² in cross section, 12.0 N/mm² in radial section and 13.7 N/mm² in tangential section respectively. The mechanical properties of Korean red pine were similar to the pine and nut pine having a similar specific gravity. The mechanical properties were greatly affected on the specific gravity than the annual ring width.