ISO 3348:1975 pdf free
ISO 3348:1975 pdf free.Wood一Determination of impact bending strength
Pendulum impact machine with a range of energy three to five times more than the work used for the impact break of the test piece and allowing the measurement of the cnergy to an accuracy of 1 J. The pendulum tup and test piece supports shall have a radius of curvature of 15 mm. The height of the supports shall be greater than 20 mm. The distance between the centres of the supports shall be 240±1 mm.
Test pieces shall be made in the form of right prisms having a square cross-section 20 mm × 20 mm and length along the grain 300 mm. One face of the test piece shall lie in a radial plane and the other in a tangential plane.
The preparation, moisture content and number of test pieces shall be in accordance with ISO 3129.
Carry out the determination of impact strength by an impact, usually, on a radial surface a tangential bending. It is permitted to carry out the determination by an impact on a tangential surface (a radial bending).
Before the test, measure the cross-sectional dimensions in the middle of the test piece to an accuracy of 0,1 mm.
The test piece, placed symmetrically on the supports, shall be broken by one impact. Measure the work absorbed by the test piece to the accuracy specified in The form of fracture conchoidal or chipped) shall be recorded in the test report. A conchoidal fracture shall be considered as one with projecting fibres of not more than 3 mm long.
After the test has been completed, determine the moisture content of the test pieces according to ISO 3130.
Take a portion 20 to 30 mm long, cut from near the fracture, as the sample for determination of moisture content. To determine the mean moisture content, it is permissible tc use only some of the test pieces. The minimum number of test pieces for moisture content dctormination shall be determined in accordance with ISO 3129.ISO 3348 pdf download.
